|
Upon
successful completion of this course, you will be able to:
- List
and discuss the current Standards of Medical Care in Diabetes
- Explain
the existing systems for the Classification and Diagnosis
of diabetes
- Discuss
the processes of DETECTION AND DIAGNOSIS OF GDM
- Explain
the differences of DIABETES CARE IN SPECIFIC POPULATIONS
- Identify
and discuss the systems for Diagnosis and Classification
of Diabetes Mellitus
- Explain
the Diabetes Care in the School and Day Care Setting
The
American Diabetes Association (ADA) has been actively involved
in the development and dissemination of diabetes care standards,
guidelines, and related documents for many years. These statements
are published in one or more of the Associations professional
journals. This supplement contains ADAs "Standards
of Medical Care in Diabetes," our major position statement,
which contains all or key recommendations. In addition, contained
herein are selected position statements on certain topics
not adequately covered in the "Standards." We hope
that this is a convenient and important resource for all health
care professionals who care for people with diabetes.
ADA
Clinical Practice Recommendations consist of position statements
that represent official ADA opinion as denoted by formal review
and approval by the Professional Practice Committee and the
Executive Committee of the Board of Directors. ADA Statements,
consensus statements, and technical reviews are not official
ADA recommendations; however, they are produced under the
auspices of the Association by invited experts. These publications
are reviewed by the Professional Practice Committee for general
content and used as source documents for the updating of the
"Standards."
ADA
has adopted the following definitions for its clinically related
reports.
An
official point of view or belief of the ADA: Position statements
are issued on scientific or medical issues related to diabetes.
They are published in ADA journals and other scientific/medical
publications as appropriate. Position statements must be reviewed
and approved by the Professional Practice Committee and, subsequently,
by the Executive Committee of the Board of Directors. ADA
position statements are typically based on a technical review
or other published review and are peer reviewed on an annual
basis.
ADA
Statement
A
focused review on a clinical topic with recommendations. It
is authored, and the recommendations are those of the authors
based on the evidence presented. ADA Statements are reviewed
externally and also by the Professional Practice Committee
for overall content. As noted above, the recommendations made
are considered by the Professional Practice Committee as part
of the review and updating of the "Standards of Medical
Care in Diabetes."
Technical
Review
A
balanced review and analysis of the literature on a scientific
or medical topic related to diabetes. The technical review
provides a scientific rationale for a position statement and
undergoes peer review before submission to the Professional
Practice Committee for approval. In some cases, in place of
a technical review, original research publications, conference
proceedings, or other comprehensive review articles are used
as a basis for a position statement.
Consensus
Statement
A
comprehensive examination by a panel of experts (i.e., consensus
panel) of a scientific or medical issue related to diabetes.
A consensus statement is developed immediately following a
consensus conference at which presentations are made on the
issue under review. The statement represents the panels
collective analysis, evaluation, and opinion based in part
on the conference proceedings. The need for a consensus conference
arises when clinicians or scientists desire guidance on a
subject for which there is a relative deficiency of "evidence"
that might otherwise allow a more definite statement to be
made. Once written by the panel, a consensus statement is
not subject to subsequent review or approval and does not
represent official Association opinion.
The
Associations Professional Practice Committee is responsible
for reviewing official position statements. Appointment to
the Professional Practice Committee is based on excellence
in clinical practice and research. The committee comprises
physicians, diabetes educators, and registered dietitians
who have expertise in a range of areas, including adult and
pediatric endocrinology, epidemiology and public health, lipid
research, hypertension, and preconception and pregnancy care.
The committee regularly reviews each previously approved statement
and makes necessary revisions. Both new and revised position
statements are also reviewed by outside experts, after which
they are approved by the Executive Committee.
Grading
of Scientific Evidence
Since the ADA first began publishing practice guidelines,
considerable evolution has occurred in the evaluation of scientific
evidence and in the development of evidence-based guidelines.
Accordingly, we have developed a classification system to
grade the quality of scientific evidence supporting ADA recommendations.
The system outlined in Table 1 will be used for all new and
revised ADA position statements.
Recommendations have been assigned ratings of A, B, or C,
depending on the quality of evidence (Table
1). Expert opinion (E) is a separate category for recommendations
in which there is as yet no evidence from clinical trials,
in which clinical trials may be impractical, or in which there
is conflicting evidence. Recommendations with an "A"
rating are based on large well-designed clinical trials or
well-done meta-analyses. Generally, these recommendations
have the best chance of improving outcomes when applied to
the population to which they are appropriate. Recommendations
with lower levels of evidence may be equally important but
are not as well supported. This supplement contains seven
statements that have used this system. The level of evidence
supporting a given recommendation is noted either as a heading
for a group of recommendations or after a given recommendation
in parentheses.
Table
1 ADA evidence grading system for clinical practice
recommendations
|
Level
of evidence
|
Description |
|
A
|
Clear
evidence from well-conducted, generalizable, randomized
controlled trials that are adequately powered, including:
Evidence from a well-conducted multicenter trial
Evidence
from a meta-analysis that incorporated quality ratings
in the analysis
Compelling nonexperimental evidence, i.e., "all
or none" rule developed by the Center for Evidence
Based Medicine at Oxford*Supportive
evidence from well-conducted randomized controlled trials
that are adequately powered, including:
Evidence from a well-conducted trial at one or more
institutions
Evidence from a meta-analysis that incorporated
quality ratings in the analysis
|
|
B
|
Supportive
evidence from well-conducted cohort studies, including:
Evidence from a well-conducted prospective cohort study
or registry
Evidence from a well-conducted meta-analysis
of cohort studiesSupportive
evidence from a well-conducted case-control study
|
|
C
|
Supportive
evidence from poorly controlled or uncontrolled studies,
including:
Evidence from randomized clinical trials with one
or more major or three or more minor methodological flaws
that could invalidate the results
Evidence from observational studies with high potential
for bias (such as case series with comparison with historical
controls)
Evidence from case series or case reports
Conflicting evidence with the weight of evidence supporting
the recommendation |
|
E
|
Expert
consensus or clinical experience |
*
Either all patients died before therapy and at least some
survived with therapy or some patients died without therapy
and none died with therapy. Example: use of insulin in the
treatment of diabetic ketoacidosis.
Of course, evidence is only one component of clinical decision-making.
Clinicians care for patients, not populations; guidelines
must always be interpreted with the needs of the individual
patient in mind. Individual circumstances, such as comorbid
and coexisting diseases, age, education, disability, and,
above all, patients values and preferences, must also
be considered and may lead to different treatment targets
and strategies. Also, conventional evidence hierarchies, such
as the one adapted by the ADA, may miss some nuances that
are important in diabetes care. For example, while there is
excellent evidence from clinical trials supporting the importance
of achieving glycemic control, the optimal way to achieve
this result is less clear. It is difficult to assess each
component of such a complex intervention.
The
ADA will continue to improve and update the Clinical Practice
Recommendations to ensure that clinicians, health plans, and
policy makers can continue to rely on them as the most authoritative
and current guidelines for diabetes care.
|
Standards
of Medical Care in Diabetes2006
|
American
Diabetes Association
Abbreviations:
ABI, ankle-brachial index AMI, acute myocatdial infarction
ARB, angiotensin receptor blocker CAD, coronary
artery disease CBG, capillary blood glucose
CHD, coronary heart disease CHF, congestive heart failure
CKD, chronic kidney disease CVD, cardiovascular
disease DCCB, dihydropyridine calcium channel blocker
DCCT, Diabetes Control and Complications Trial
DKA, diabetic ketoacidosis DMMP, diabetes medical management
plan DPN, distal symmetric polyneuropathy DPP,
Diabetes Prevention Program DRI, dietary reference
intake DRS, Diabetic Retinopathy Study DSME,
diabetes self-management education DSMT, diabetes self-management
training ECG, electrocardiogram ESRD, end-stage
renal disease ETDRS, Early Treatment Diabetic Retinopathy
Study FDA, Food and Drug Administration FPG,
fasting plasma glucose GDM, gestational diabetes mellitus
GFR, glomerular filtration rate HRC, high-risk
characteristic ICU, intensive care unit IFG,
impaired fasting glucose IGT, impaired glucose tolerance
MNT, medical nutrition therapy NPDR, nonproliferative
diabetic retinopathy OGTT, oral glucose tolerance test
PAD, peripheral arterial disease PDR, proliferative
diabetic retinopathy PPG, postprandial plasma glucose
RDA, recommended dietary allowance SMBG, self-monitoring
of blood glucose TZD, thiazolidinedione
Diabetes
is a chronic illness that requires continuing medical care
and patient self-management education to prevent acute complications
and to reduce the risk of long-term complications. Diabetes
care is complex and requires that many issues, beyond glycemic
control, be addressed. A large body of evidence exists that
supports a range of interventions to improve diabetes outcomes.
These
standards of care are intended to provide clinicians, patients,
researchers, payors, and other interested individuals with
the components of diabetes care, treatment goals, and tools
to evaluate the quality of care. While individual preferences,
comorbidities, and other patient factors may require modification
of goals, targets that are desirable for most patients with
diabetes are provided. These standards are not intended to
preclude more extensive evaluation and management of the patient
by other specialists as needed.
The
recommendations included are diagnostic and therapeutic actions
that are known or believed to favorably affect health outcomes
of patients with diabetes. A grading system (Table
1), developed by the American Diabetes Association (ADA)
and modeled after existing methods, was utilized to clarify
and codify the evidence that forms the basis for the recommendations.
The level of evidence that supports each recommendation is
listed after each recommendation using the letters A, B, C,
or E.
|
I.
Classification and Diagnosis
|
A.
Classification
In
1997, the ADA issued new diagnostic and classification criteria;
in 2003, modifications were made regarding the diagnosis of
impaired fasting glucose (IFG). The classification of diabetes
includes four clinical classes:
- Type
1 diabetes (results from ß-cell destruction, usually
leading to absolute insulin deficiency).
- Type
2 diabetes (results from a progressive insulin secretory
defect on the background of insulin resistance).
- Other
specific types of diabetes due to other causes, e.g., genetic
defects in ß-cell function, genetic defects in insulin
action, diseases of the exocrine pancreas (such as cystic
fibrosis), and drug or chemical induced (such as in the
treatment of AIDS or after organ transplantation).
- Gestational
diabetes mellitus (GDM) (diagnosed during pregnancy).
B. Diagnosis
Recommendations
- The
FPG is the preferred test to diagnose diabetes in children
and nonpregnant adults. (E)
- The
use of the A1C for the diagnosis of diabetes is not recommended
at this time. (E)
Criteria
for the diagnosis of diabetes in nonpregnant adults are shown
in Table 2. Three ways to diagnose diabetes are available,
and each must be confirmed on a subsequent day unless unequivocal
symptoms of hyperglycemia are present. Although the 75-g oral
glucose tolerance test (OGTT) is more sensitive and modestly
more specific than fasting plasma glucose (FPG) to diagnose
diabetes, it is poorly reproducible and rarely performed in
practice. Because of ease of use, acceptability to patients,
and lower cost, the FPG is the preferred diagnostic test.
It should be noted that the vast majority of people who meet
diagnostic criteria for diabetes by OGTT, but not by FPG,
will have an A1C value <7.0%. The use of the A1C for the
diagnosis of diabetes is not recommended at this time.
Table
2 Criteria for the diagnosis of diabetes
|
1.
|
Symptoms
of diabetes and a casual plasma glucose 200 mg/dl (11.1
mmol/l). Casual is defined as any time of day without
regard to time since last meal. The classic symptoms
of diabetes include polyuria, polydipsia, and unexplained
weight loss. OR
|
|
2.
|
FPG
126 mg/dl (7.0 mmol/l). Fasting is defined as no caloric
intake for at least 8 h. OR
|
|
3.
|
2-h
plasma glucose 200 mg/dl (11.1 mmol/l) during an OGTT.
The test should be performed as described by the World
Health Organization, using a glucose load containing the
equivalent of 75-g anhydrous glucose dissolved in water. |
Hyperglycemia
not sufficient to meet the diagnostic criteria for diabetes
is categorized as either IFG or impaired glucose tolerance
(IGT), depending on whether it is identified through a FPG
or an OGTT:
- IFG
= FPG 100 mg/dl (5.6 mmol/l) to 125 mg/dl (6.9 mmol/l)
- IGT
= 2-h plasma glucose 140 mg/dl (7.8 mmol/l) to 199 mg/dl
(11.0 mmol/l)
Recently,
IFG and IGT have been officially termed "pre-diabetes."
Both categories, IFG and IGT, are risk factors for future
diabetes and cardiovascular disease (CVD).
In
the absence of unequivocal hyperglycemia, these criteria should
be confirmed by repeat testing on a different day. The OGTT
is not recommended for routine clinical use but may be required
in the evaluation of patients with IFG (see text) or when
diabetes is still suspected despite a normal FPG, as with
the postpartum evaluation of women with GDM.
|
II.
Screening for Diabetes
|
Recommendations
- Screening
to detect pre-diabetes (IFG or IGT) and diabetes should
be considered in individuals 45 years of age, particularly
in those with a BMI 25 kg/m2. Screening should also be considered
for people who are <45 years of age and are overweight
if they have another risk factor for diabetes (Table
3). Repeat testing should be carried out at 3-year intervals.
(E)
- Screen
for pre-diabetes and diabetes in high-risk, asymptomatic,
undiagnosed adults and children within the health care setting.
(E)
- To
screen for diabetes/pre-diabetes, either an FPG test or
2-h OGTT (75-g glucose load) or both are appropriate. (B)
- An
OGTT may be considered in patients with IFG to better define
the risk of diabetes. (E)
Table
3 Criteria for testing for diabetes in asymptomatic
adult individuals
|
1.
|
Testing
for diabetes should be considered in all individuals
at age 45 years and above, particularly in those with
a BMI 25 kg/m2*, and, if normal, should be repeated
at 3-year intervals. |
|
2.
|
Testing
should be considered at a younger age or be carried
out more frequently in individuals who are overweight
(BMI 25 kg/m2*) and have additional risk factors:
are habitually physically inactive
have a first-degree relative with diabetes
are members of a high-risk ethnic population
(e.g., African American, Latino, Native American, Asian
American, Pacific Islander)
have delivered a baby weighing >9 lb or have
been diagnosed with GDM
are hypertensive ( 140/90 mmHg)
have an HDL cholesterol level <35 mg/dl (0.90
mmol/l) and/or a triglyceride level >250 mg/dl (2.82
mmol/l)
have PCOS
on previous testing, had IGT or IFG
have other clinical conditions associated with
insulin resistance (e.g. PCOS or acanthosis nigricans)
have a history of vascular disease |
*
May not be correct for all ethnic groups. PCOS, polycystic
ovary syndrome.
There is a major distinction between diagnostic testing and
screening. Both utilize the same clinical tests, which should
be done within the context of the health care setting. When
an individual exhibits symptoms or signs of the disease, diagnostic
tests are performed, and such tests do not represent screening.
The purpose of screening is to identify asymptomatic individuals
who are likely to have diabetes or pre-diabetes. Separate
diagnostic tests using standard criteria are required after
positive screening tests to establish a definitive diagnosis
as described above.
Type
1 diabetes
Generally,
people with type 1 diabetes present with acute symptoms of
diabetes and markedly elevated blood glucose levels. Because
of the acute onset of symptoms, most cases of type 1 diabetes
are detected soon after symptoms develop. Widespread clinical
testing of asymptomatic individuals for the presence of autoantibodies
related to type 1 diabetes cannot be recommended at this time
as a means to identify individuals at risk. Reasons for this
include the following:
- cutoff
values for some of the immune marker assays have not been
completely established in clinical settings;
- there
is no consensus as to what action should be taken when a
positive autoantibody test result is obtained; and
- because
the incidence of type 1 diabetes is low, testing of healthy
children will identify only a very small number (<0.5%)
who at that moment may be "pre-diabetic." Clinical
studies are being conducted to test various methods of preventing
type 1 diabetes in high-risk individuals (e.g., siblings
of type 1 diabetic patients). These studies may uncover
an effective means of preventing type 1 diabetes, in which
case targeted screening may be appropriate in the future.
Type
2 diabetes
Type
2 diabetes is frequently not diagnosed until complications
appear, and approximately one-third of all people with diabetes
may be undiagnosed. Individuals at high risk should be screened
for diabetes and pre-diabetes. Criteria for testing for diabetes
in asymptomatic, undiagnosed adults are listed in Table
3. The effectiveness of early diagnosis through screening
of asymptomatic individuals has not been determined.
Screening
should be carried out within the health care setting. Either
an FPG test or 2-h OGTT (75-g glucose load) is appropriate.
The 2-h OGTT identifies people with IGT, and thus, more people
who are at increased risk for the development of diabetes
and CVD. It should be noted that the two tests do not necessarily
detect the same individuals. It is important to recognize
that although the efficacy of interventions for primary prevention
of type 2 diabetes have been demonstrated among individuals
with IGT, such data among individuals with IFG (who do not
also have IGT) are not available. The FPG test is more convenient
to patients, more reproducible, less costly, and easier to
administer than the 2-h OGTT. Therefore, the recommended initial
screening test for nonpregnant adults is the FPG. An OGTT
may be considered in patients with IFG to better define the
risk of diabetes. The incidence of type 2 diabetes in children
and adolescents has increased dramatically in the last decade.
Consistent with screening recommendations for adults, only
children and youth at increased risk for the presence or the
development of type 2 diabetes should be tested (Table
4).
Table
4 Testing for type 2 diabetes in children
Criteria:
- Overweight
(BMI >85th percentile for age and sex, weight for height
>85th percentile, or weight >120% of ideal for height)
Plus
any two of the following risk factors:
- Family
history of type 2 diabetes in first- or second-degree relative
- Race/ethnicity
(Native American, African American, Latino, Asian American,
Pacific Islander)
- Signs
of insulin resistance or conditions associated with insulin
resistance (acanthosis nigricans, hypertension, dyslipidemia,
or PCOS)
- Maternal
history of diabetes or GDM
Age
of initiation: age 10 years or at onset of puberty, if puberty
occurs at a younger age
Frequency: every 2 years
Test: FPG preferred
Clinical
judgment should be used to test for diabetes in high-risk
patients who do not meet these criteria. PCOS, polycystic
ovary syndrome.
The
effectiveness of screening may also depend on the setting
in which it is performed. In general, community screening
outside a health care setting may be less effective because
of the failure of people with a positive screening test to
seek and obtain appropriate follow-up testing and care or,
conversely, to ensure appropriate repeat testing for individuals
who screen negative. That is, screening outside of clinical
settings may yield abnormal tests that are never discussed
with a primary care provider, low compliance with treatment
recommendations, and a very uncertain impact on long-term
health. Community screening may also be poorly targeted, i.e.,
it may fail to reach the groups most at risk and inappropriately
test those at low risk (the worried well) or even those already
diagnosed.
On
the basis of expert opinion, screening should be considered
by health care providers at 3-year intervals beginning at
age 45, particularly in those with BMI 25 kg/m2. The rationale
for this interval is that false negatives will be repeated
before substantial time elapses, and there is little likelihood
of an individual developing any of the complications of diabetes
to a significant degree within 3 years of a negative screening
test result. Testing should be considered at a younger age
or be carried out more frequently in individuals who are overweight
and have one or more of the other risk factors for type 2
diabetes.
|
III.
DETECTION AND DIAGNOSIS OF GDM
|
Recommendations
- Screen
for diabetes in pregnancy using risk factor analysis and,
if appropriate, use of an OGTT. (C)
- Women
with GDM should be screened for diabetes 612 weeks
postpartum and should be followed up with subsequent screening
for the development of diabetes or pre-diabetes. (E)
Risk
assessment for GDM should be undertaken at the first prenatal
visit. Women with clinical characteristics consistent with
a high risk for GDM (those with marked obesity, personal history
of GDM, glycosuria, or a strong family history of diabetes)
should undergo glucose testing as soon as possible. An FPG
126 mg/dl or a casual plasma glucose 200 mg/dl meets the threshold
for the diagnosis of diabetes and needs to be confirmed on
a subsequent day unless unequivocal symptoms of hyperglycemia
are present. High-risk women not found to have GDM at the
initial screening and average-risk women should be tested
between 24 and 28 weeks of gestation. Testing should follow
one of two approaches:
- One-step
approach: perform a diagnostic 100-g OGTT
- Two-step
approach: perform an initial screening by measuring the
plasma or serum glucose concentration 1 h after a 50-g oral
glucose load (glucose challenge test) and perform a diagnostic
100-g OGTT on that subset of women exceeding the glucose
threshold value on the glucose challenge test. When the
two-step approach is used, a glucose threshold value 140
mg/dl identifies 80% of women with GDM, and the yield is
further increased to 90% by using a cutoff of 130 mg/dl.
Diagnostic
criteria for the 100-g OGTT are as follows: 95 mg/dl fasting,
180 mg/dl at 1 h, 155 mg/dl at 2 h, and 140 mg/dl at 3 h.
Two or more of the plasma glucose values must be met or exceeded
for a positive diagnosis. The test should be done in the morning
after an overnight fast of 814 h. The diagnosis can
be made using a 75-g glucose load, but that test is not as
well validated for detection of at-risk infants or mothers
as the 100-g OGTT.
Low-risk
status requires no glucose testing, but this category is limited
to those women meeting all of the following characteristics:
- Age
<25 years.
- Weight
normal before pregnancy.
- Member
of an ethnic group with a low prevalence of GDM.
- No
known diabetes in first-degree relatives.
- No
history of abnormal glucose tolerance.
- No
history of poor obstetric outcome.
|
IV.
PREVENTION/DELAY OF TYPE 2 DIABETES
|
Recommendations
- Individuals
at high risk for developing diabetes need to become aware
of the benefits of modest weight loss and participating
in regular physical activity. (A)
- Patients
with IGT should be given counseling on weight loss as well
as instruction for increasing physical activity. (A)
- Patients
with IFG should be given counseling on weight loss as well
as instruction for increasing physical activity. (E)
- Follow-up
counseling appears important for success. (B)
- Monitoring
for the development of diabetes in those with pre-diabetes
should be performed every 12 years. (E)
- Close
attention should be given to, and appropriate treatment
given for, other CVD risk factors (e.g., tobacco use, hypertension,
dyslipidemia). (A)
- Drug
therapy should not be routinely used to prevent diabetes
until more information is known about its cost-effectiveness.
(E)
Studies
have been initiated in the last decade to determine the feasibility
and benefit of various strategies to prevent or delay the
onset of type 2 diabetes. Five well-designed randomized controlled
trials have been reported. The strategies shown to be effective
in preventing diabetes relied on lifestyle modification or
glucose-lowering drugs that have been approved for treating
diabetes.
In
the Finnish study, middle-aged obese subjects with IGT were
randomized to receive either brief diet and exercise counseling
(control group) or intensive individualized instruction on
weight reduction, food intake, and guidance on increasing
physical activity (intervention group). After an average follow-up
of 3.2 years, there was a 58% relative reduction in the incidence
of diabetes in the intervention group compared with the control
subjects.
In
the Diabetes Prevention Program (DPP), enrolled subjects were
slightly younger and more obese but had nearly identical glucose
intolerance compared with subjects in the Finnish study. About
45% of the participants were from minority groups (e.g., African
American, Hispanic), and 20% were 60 years of age. Subjects
were randomized to one of three intervention groups, which
included the intensive nutrition and exercise counseling ("lifestyle")
group or either of two masked medication treatment groups:
the biguanide metformin group or the placebo group. The latter
interventions were combined with standard diet and exercise
recommendations. After an average follow-up of 2.8 years,
a 58% relative reduction in the progression to diabetes was
observed in the lifestyle group and a 31% relative reduction
in the progression of diabetes was observed in the metformin
group compared with control subjects. On average, 50% of the
lifestyle group achieved the goal of 7% weight reduction and
74% maintained at least 150 min/week of moderately intense
activity. In the troglitazone arm of the DPP (discontinued
after a mean of 0.9 years when the drug was withdrawn from
the market), troglitazone markedly reduced the incidence of
diabetes during the period the drug was given.
In
the Da Qing Study, men and women from health care clinics
in the city of Da Qing, China, were screened with OGTT, and
those with IGT were randomized by clinic to a control group
or to one of three active treatment groups: diet only, exercise
only, or diet plus exercise. Subjects were reexamined biannually,
and after an average of 6 years follow-up, the diet,
exercise, and diet plus exercise interventions were associated
with 31, 46, and 42% reductions in risk of developing type
2 diabetes, respectively.
Three
other studies, each using a different class of glucose-lowering
agent, have shown a reduction in progression to diabetes with
pharmacological intervention. In the Troglitazone in Prevention
of Diabetes (TRIPOD) study, Hispanic women with previous GDM
were randomized to receive either placebo or troglitazone
(a drug now withdrawn from commercial sale in the U.S. but
belonging to the thiazolidinedione [TZD] class). After a median
follow-up of 30 months, troglitazone treatment was associated
with a 56% relative reduction in progression to diabetes.
In the STOP-IDDM trial, participants with IGT were randomized
in a double-blind fashion to receive either the -glucosidase
inhibitor acarbose or a placebo. After a mean follow-up of
3.3 years, a 25% relative risk reduction in progression to
diabetes, based on one OGTT, was observed in the acarbose-treated
group compared with the placebo group. If this diagnosis was
confirmed by a second OGTT, a 36% relative risk reduction
was observed in the acarbose group compared with the placebo
group.
Finally,
in the XENical in the prevention of Diabetes in Obese Subjects
(XENDOS) study, orlistat was examined for its ability to delay
type 2 diabetes when added to lifestyle change in a group
with BMI 30 kg/m2 with or without IGT. After 4 years of treatment,
the effect of orlistat addition corresponded to a 45% risk
reduction in the IGT group, with no effect observed in those
without IGT.
Our
knowledge of the early stages of hyperglycemia that portend
the diagnosis of diabetes, and the recent success of major
intervention trials, clearly show that individuals at high
risk can be identified and diabetes delayed, if not prevented.
The cost-effectiveness of intervention strategies is unclear,
but the huge burden resulting from the complications of diabetes
and the potential ancillary benefits of some of the interventions
suggest that an effort to prevent diabetes is worthwhile.
Lifestyle
modification
In
well-controlled studies that included a lifestyle intervention
arm, substantial efforts were necessary to achieve only modest
changes in weight and exercise, but those changes were sufficient
to achieve an important reduction in the incidence of diabetes.
In the Finnish Diabetes Prevention Study, weight loss averaged
9.2 lb at 1 year, 7.7 lb after 2 years, and 4.6 lb after 5
years; "moderate exercise," such as brisk walking,
for 30 min/day was suggested. In the Finnish study, there
was a direct relationship between adherence with the lifestyle
intervention and the reduced incidence of diabetes.
In
the DPP, the lifestyle group lost 12 lb at 2 years and 9 lb
at 3 years (mean weight loss for the study duration was 12
lb or 6% of initial body weight). In both of these studies,
most of the participants were obese (BMI >30 kg/m2).
A
low-fat (<25% fat) intake was recommended; if reducing
fat did not produce weight loss to goal, calorie restriction
was also recommended. Participants weighing 120174 lb
(5478 kg) at baseline were instructed to follow a 1,200-kcal/day
diet (33 g fat), those 175219 lb (7999 kg) were
instructed to follow a 1,500-kcal/day diet (42 g fat), those
220249 lb (100113 kg) were instructed to follow
an 1,800-kcal/day diet (50 g fat), and those >250 lb (114
kg) were instructed to follow a 2,000-kcal/day diet (55 g
fat).
Pharmacological
interventions
Three
diabetes prevention trials used pharmacological therapy, and
all have reported a significant lowering of the incidence
of diabetes. The biguanide metformin reduced the risk of diabetes
by 31% in the DPP, the -glucosidase inhibitor acarbose reduced
the risk by 32% in the STOP-IDDM trial, and the TZD troglitazone
reduced the risk by 56% in the TRIPOD study.
In
the DPP, metformin was about half as effective as diet and
exercise in delaying the onset of diabetes overall, but it
was nearly ineffective in older individuals ( 60 years of
age) or in those who were less overweight (BMI <30 kg/m2).
Conversely, metformin was as effective as lifestyle modification
in individuals aged 2444 years or in those with a BMI
35 kg/m2. Thus, the population of people in whom treatment
with metformin has equal benefit to that of a lifestyle intervention
is only a small subset of those who are likely to have pre-diabetes
(IFG or IGT).
There
are also data to suggest that blockade of the renin-angiotensin
system may lower the risk of developing diabetes, but more
studies are necessary before these drugs can be recommended
for preventing diabetes.
Lifestyle
or medication?
The
DPP is the only study in which a comparison of the two was
made, and lifestyle modification was nearly twice as effective
in preventing diabetes (58 vs. 31% relative reductions, respectively).
The greater benefit of weight loss and physical activity strongly
suggests that lifestyle modification should be the first choice
to prevent or delay diabetes. Modest weight loss (510%
of body weight) and modest physical activity (30 min daily)
are the recommended goals. Because this intervention not only
has been shown to prevent or delay diabetes, but also has
a variety of other benefits, health care providers should
urge all overweight or sedentary individuals to adopt these
changes, and such recommendations should be made at every
opportunity.
When
all factors are considered, there is insufficient evidence
to support the use of drug therapy as a substitute for, or
routinely used in addition to, lifestyle modification to prevent
diabetes. Public health messages, health care professionals,
and health care systems should all encourage behavior changes
to achieve a healthy lifestyle. Further research is necessary
to understand better how to facilitate effective and efficient
programs for the primary prevention of type 2 diabetes.
A.
Initial evaluation
A
complete medical evaluation should be performed to classify
the patient, detect the presence or absence of diabetes complications,
assist in formulating a management plan, and provide a basis
for continuing care. If the diagnosis of diabetes has already
been made, the evaluation should review the previous treatment
and the past and present degrees of glycemic control. Laboratory
tests appropriate to the evaluation of each patients
general medical condition should be performed. A focus on
the components of comprehensive care (Table 5) will assist
the health care team to ensure optimal management of the patient
with diabetes.
Table
5 Components of the comprehensive diabetes evaluation
Medical
history
- Symptoms,
results of laboratory tests, and special examination results
related to the diagnosis of diabetes
- Prior
A1C records
- Eating
patterns, nutritional status, and weight history; growth
and development in children and adolescents
- Details
of previous treatment programs, including nutrition and
diabetes self-management education, attitudes, and health
beliefs
- Current
treatment of diabetes, including medications, meal plan,
and results of glucose monitoring and patients use
of data
- Exercise
history
- Frequency,
severity, and cause of acute complications such as ketoacidosis
and hypoglycemia
- Prior
or current infections, particularly skin, foot, dental,
and genitourinary infections
- Symptoms
and treatment of chronic eye; kidney; nerve; genitourinary
(including sexual), bladder, and gastrointestinal function
(including symptoms of celiac disease in type 1 diabetic
patients); heart; peripheral vascular; foot; and cerebrovascular
complications associated with diabetes
- Other
medications that may affect blood glucose levels
- Risk
factors for atherosclerosis: smoking, hypertension, obesity,
dyslipidemia, and family history
- History
and treatment of other conditions, including endocrine and
eating disorders
- Assessment
for mood disorder
- Family
history of diabetes and other endocrine disorders
- Lifestyle,
cultural, psychosocial, educational, and economic factors
that might influence the management of diabetes
- Tobacco,
alcohol, and/or controlled substance use
- Contraception
and reproductive and sexual history
Physical
examination
- Height
and weight measurement (and comparison to norms in children
and adolescents)
- Sexual
maturation staging (during pubertal period)
- Blood
pressure determination, including orthostatic measurements
when indicated, and comparison to age-related norms
- Fundoscopic
examination
- Oral
examination
- Thyroid
palpation
- Cardiac
examination
- Abdominal
examination (e.g., for hepatomegaly)
- Evaluation
of pulses by palpation and with auscultation
- Hand/finger
examination
- Foot
examination
- Skin
examination (for acanthosis nigricans and insulin-injection
sites)
- Neurological
examination
- Signs
of diseases that can cause secondary diabetes (e.g., hemochromatosis,
pancreatic disease)
Laboratory
evaluation
- A1C
- Fasting
lipid profile, including total cholesterol, HDL cholesterol,
triglycerides, and LDL cholesterol, liver function tests
with further evaluation for fatty liver or hepatitis if
abnormal
- Test
for microalbuminuria in type 1 diabetic patients who have
had diabetes for at least 5 years and in all patients with
type 2 diabetes; some advocate beginning screening of pubertal
children before 5 years of diabetes
- Serum
creatinine and calculated GFR in adults (check creatinine
in children if proteinuria is present)
- Thyroid-stimulating
hormone (TSH) in all type 1 diabetic patients; in type 2
if clinically indicated
- Electrocardiogram
in adults, if clinically indicated
- Urinalysis
for ketones, protein, sediment
Referrals
- Eye
exam, if indicated
- Family
planning for women of reproductive age
- MNT,
as indicated
- Diabetes
educator, if not provided by physician or practice staff
- Behavioral
specialist, as indicated
- Foot
specialist, as indicated
- Other
specialties and services as appropriate
B.
Management
People
with diabetes should receive medical care from a physician-coordinated
team. Such teams may include, but are not limited to, physicians,
nurse practitioners, physicians assistants, nurses,
dietitians, pharmacists, and mental health professionals with
expertise and a special interest in diabetes. It is essential
in this collaborative and integrated team approach that individuals
with diabetes assume an active role in their care.
The
management plan should be formulated as an individualized
therapeutic alliance among the patient and family, the physician,
and other members of the health care team. Any plan should
recognize diabetes self-management education (DSME) as an
integral component of care. In developing the plan, consideration
should be given to the patients age, school or work
schedule and conditions, physical activity, eating patterns,
social situation and personality, cultural factors, and presence
of complications of diabetes or other medical conditions.
A variety of strategies and techniques should be used to provide
adequate education and development of problem-solving skills
in the various aspects of diabetes management. Implementation
of the management plan requires that each aspect is understood
and agreed on by the patient and the care providers and that
the goals and treatment plan are reasonable.
C.
Glycemic control
1.
Assessment of glycemic control
Techniques
are available for health providers and patients to assess
the effectiveness of the management plan on glycemic control.
a.
Self-monitoring of blood glucose
Recommendations
- Clinical
trials using insulin that have demonstrated the value of
tight glycemic control have used self-monitoring of blood
glucose (SMBG) as an integral part of the management strategy.
(A)
- SMBG
should be carried out three or more times daily for patients
using multiple insulin injections. (A)
- For
patients using less frequent insulin injections or oral
agents or medical nutrition therapy (MNT) alone, SMBG is
useful in achieving glycemic goals. (E)
- To
achieve postprandial glucose targets, postprandial SMBG
may be appropriate. (E)
- Instruct
the patient in SMBG and routinely evaluate the patients
technique and ability to use data to adjust therapy. (E)
The
ADAs consensus statements on SMBG provide a comprehensive
review of the subject. Major clinical trials assessing the
impact of glycemic control on diabetes complications have
included SMBG as part of multifactorial interventions, suggesting
that SMBG is a component of effective therapy. SMBG allows
patients to evaluate their individual response to therapy
and assess whether glycemic targets are being achieved. Results
of SMBG can be useful in preventing hypoglycemia and adjusting
medications, MNT, and physical activity.
The
frequency and timing of SMBG should be dictated by the particular
needs and goals of the patients. Daily SMBG is especially
important for patients treated with insulin to monitor for
and prevent asymptomatic hypoglycemia and hyperglycemia. For
most patients with type 1 diabetes and pregnant women taking
insulin, SMBG is recommended three or more times daily. The
optimal frequency and timing of SMBG for patients with type
2 diabetes on oral agent therapy is not known but should be
sufficient to facilitate reaching glucose goals. Patients
with type 2 diabetes on insulin typically need to perform
SMBG more frequently than those not using insulin. When adding
to or modifying therapy, type 1 and type 2 diabetic patients
should test more often than usual. The role of SMBG in stable
diet-treated patients with type 2 diabetes is not known.
Because
the accuracy of SMBG is instrument and user dependent, it
is important for health care providers to evaluate each patients
monitoring technique, both initially and at regular intervals
thereafter. In addition, optimal use of SMBG requires proper
interpretation of the data. Patients should be taught how
to use the data to adjust food intake, exercise, or pharmacological
therapy to achieve specific glycemic goals. Health professionals
should evaluate at regular intervals the patients ability
to use SMBG data to guide treatment.
b.
A1C
Recommendations
- Perform
the A1C test at least two times a year in patients who are
meeting treatment goals (and who have stable glycemic control).
(E)
- Perform
the A1C test quarterly in patients whose therapy has changed
or who are not meeting glycemic goals. (E)
- Use
of point-of-care testing for A1C allows for timely decisions
on therapy changes, when needed. (E)
By
performing an A1C test, health providers can measure a patients
average glycemia over the preceding 23 months and, thus,
assess treatment efficacy. A1C testing should be performed
routinely in all patients with diabetes, first to document
the degree of glycemic control at initial assessment and then
as part of continuing care. Since the A1C test reflects mean
glycemia over the preceding 23 months, measurement approximately
every 3 months is required to determine whether a patients
metabolic control has been reached and maintained within the
target range. Thus, regular performance of the A1C test permits
detection of departures from the target (Table
6) in a timely fashion. For any individual patient, the
frequency of A1C testing should be dependent on the clinical
situation, the treatment regimen used, and the judgment of
the clinician.
Table
6 Summary of recommendations for adults with diabetes
| Glycemic
control |
|
| |
A1C |
<7.0%* |
| |
Preprandial
capillary plasma glucose |
90130
mg/dl (5.07.2 mmol/l) |
| |
Peak
postprandial capillary plasma glucose |
<180
mg/dl (<10.0 mmol/l) |
| |
Blood
pressure |
<130/80
mmHg |
| Lipids
|
|
| |
LDL |
<100 mg/dl (<2.6 mmol/l) |
| |
Triglycerides
|
<150
mg/dl (<1.7 mmol/l) |
| |
HDL
|
>40
mg/dl (>1.1 mmol/l) |
Key
concepts in setting glycemic goals:
- A1C
is the primary target for glycemic control
- Goals
should be individualized
- Certain
populations (children, pregnant women, and elderly) require
special considerations
-
More stringent glycemic goals (i.e., a normal A1C, <6%)
may further reduce complications at the cost of increased
risk of hypoglycemia
- Less
intensive glycemic goals may be indicated in patients with
severe or frequent hypoglycemia
- Postprandial
glucose may be targeted if A1C goals are not met despite
reaching preprandial glucose goals
*
Referenced to a nondiabetic range of 4.06.0% using a
DCCT-based assay.
**
Postprandial glucose measurements should be made 12
h after the beginning of the meal, generally peak levels in
patients with diabetes.
^
Current NCEP/ATP III guidelines suggest that in patients with
triglycerides 200 mg/dl, the "non-HDL cholesterol"
(total cholesterol minus HDL) be utilized. The goal is 130
mg/dl (34).
$
For women, it has been suggested that the HDL goal be increased
by 10 mg/dl.
The
A1C test is subject to certain limitations. Conditions that
affect erythrocyte turnover (hemolysis, blood loss) and hemoglobin
variants must be considered, particularly when the A1C result
does not correlate with the patients clinical situation.
The availability of the A1C result at the time that the patient
is seen (point of care testing) has been reported to result
in the frequency of intensification of therapy and improvement
in glycemic control.
Glycemic
control is best judged by the combination of the results of
the patients SMBG testing (as performed) and the current
A1C result. The A1C should be used not only to assess the
patients control over the preceding 23 months
but also as a check on the accuracy of the meter (or the patients
self-reported results) and the adequacy of the SMBG testing
schedule. Table
7 contains the correlation between A1C levels and mean
plasma glucose levels based on data from the Diabetes Control
and Complications Trial (DCCT).
Table
7 Correlation between A1C level and mean plasma glucose
levels on multiple testing over 23 months (23)
|
A1C
(%)
|
Mean
plasma glucose
|
|
|
mg/dl
|
mmol/l
|
|
6
|
135
|
7.5
|
|
7
|
170
|
9.5
|
|
8
|
205
|
11.5
|
|
9
|
240
|
13.5
|
|
10
|
275
|
15.5
|
|
11
|
310
|
17.5
|
|
12
|
345
|
19.5
|
|
2.
Glycemic goals
Recommendations
- Lowering
A1C has been associated with a reduction of microvascular
and neuropathic complications of diabetes. (A)
- The
A1C goal for patients in general is an A1C goal of <7%.
(B)
- The
A1C goal for the individual patient is an A1C as close to
normal (<6%) as possible without significant hypoglycemia.
(E)
- Less
stringent treatment goals may be appropriate for patients
with a history of severe hypoglycemia, patients with limited
life expectancies, very young children or older adults,
and individuals with comorbid conditions. (E)
- Aggressive
glycemic management with insulin may reduce morbidity in
patients with severe acute illness, perioperatively, following
myocardial infarction, and in pregnancy. (B)
Glycemic
control is fundamental to the management of diabetes. The
goal of therapy is to acheive an A1C as close to normal as
possible (representing normal fasting and postprandial glucose
concentrations) in the absence of hypoglycemia. However, this
goal is difficult to achieve with present therapies. Prospective
randomized clinical trials such as the DCCT and the U.K. Prospective
Diabetes Study (UKPDS) have shown that improved glycemic control
is associated with sustained decreased rates of retinopathy,
nephropathy, and neuropathy. In these trials, treatment regimens
that reduced average A1C to 7% (1% above the upper limits
of normal) were associated with fewer long-term microvascular
complications; however, intensive control was found to increase
the risk of severe hypoglycemia and weight gain. The potential
of intensive glycemic control to reduce CVD is supported by
epidemiological studies and a recent meta-analysis, but this
potential benefit on CVD events has not yet been demonstrated
in a randomized clinical trial.
Recommended
glycemic goals for nonpregnant individuals are shown in Table
6. A major limitation to the available data is that they
do not identify the optimum level of control for particular
patients, as there are individual differences in the risks
of hypoglycemia, weight gain, and other adverse effects. Furthermore,
with multifactorial interventions, it is unclear how different
components (e.g., educational interventions, glycemic targets,
lifestyle changes, pharmacological agents) contribute to the
reduction of complications. There are no clinical trial data
available for the effects of glycemic control in patients
with advanced complications, the elderly ( 65 years of age),
or young children (<13 years of age). Less stringent treatment
goals may be appropriate for patients with limited life expectancies,
in the very young or older adults, and in individuals with
comorbid conditions. Severe or frequent hypoglycemia is an
indication for the modification of treatment regimens, including
setting higher glycemic goals.
More
stringent goals (i.e., a normal A1C, <6%) should be considered
in individual patients based on epidemiological analyses suggesting
that there is no lower limit of A1C at which further lowering
does not reduce the risk of complications, at the risk of
increased hypoglycemia (particularly in those with type 1
diabetes). However, the absolute risks and benefits of lower
targets are unknown. The risks and benefits of an A1C goal
of <6% are currently being tested in an ongoing study (ACCORD
[Action to Control Cardiovascular Risk in Diabetes]) in type
2 diabetes.
Elevated
postchallenge (2-h OGTT) glucose values have been associated
with increased cardiovascular risk independent of FPG in some
epidemiological studies. Postprandial plasma glucose (PPG)
levels >140 mg/dl are unusual in nondiabetic individuals,
although large evening meals can be followed by plasma glucose
values up to 180 mg/dl. There are now pharmacological agents
that primarily modify PPG and thereby reduce A1C in parallel.
Thus, in individuals who have premeal glucose values within
target but who are not meeting A1C targets, consideration
of monitoring PPG 12 h after the start of the meal and
treatment aimed at reducing PPG values <180 mg/dl may lower
A1C. However, it should be noted that the effect of these
approaches on micro- or macrovascular complications has not
been studied.
As
regards goals for glycemic control for women with GDM, recommendations
from the Fourth International Workshop-Conference on Gestational
Diabetes suggest lowering maternal capillary blood glucose
concentrations to 95 mg/dl (5.3 mmol/l) fasting, 140 mg/dl
(7.8 mmol/l) at 1 h, and/or 120 mg/dl (6.7 mmol/l) at 2 h
after the meal. For further information on GDM, refer to the
ADA position statement.
D.
MNT
Recommendations
- People
with diabetes should receive individualized MNT as needed
to achieve treatment goals, preferably provided by a registered
dietitian familiar with the components of diabetes MNT.
(B)
- Both
the amount (grams) of carbohydrate as well as the type of
carbohydrate in a food influence blood glucose level. Monitoring
total grams of carbohydrate, whether by use of exchanges
or carbohydrate counting, remains a key strategy in achieving
glycemic control. (A)
- The
use of the glycemic index/glycemic load may provide an additional
benefit over that observed when total carbohydrate is considered
alone. (B)
- Low-carbohydrate
diets (restricting total carbohydrate to <130 g/day)
are not recommended in the management of diabetes. (E)
- To
reduce the risk of nephropathy, protein intake should be
limited to the recommended dietary allowance (RDA) (0.8
g/kg) in those with any degree of CKD. (B)
- Saturated
fat intake should be <7% of total calories. (A)
- Intake
of trans fat should be minimized. (E)
- Weight
loss is recommended for all overweight (BMI 25.029.9
kg/m2) or obese (BMI 30.0 kg/m2) adults who have, or are
at risk for developing, type 2 diabetes. (E)
- The
primary approach for achieving weight loss is therapeutic
lifestyle change, which includes a reduction in energy intake
and an increase in physical activity. A moderate decrease
in caloric balance (5001,000 kcal/day) will result
in a slow but progressive weight loss (12 lb/week).
For most patients, weight loss diets should supply at least
1,0001,200 kcal/day for women and 1,2001,600
kcal/day for men. (E)
- Initial
physical activity recommendations should be modest and based
on the patients willingness and ability, gradually
increasing the duration and frequency to 3045 min
of moderate aerobic activity, 35 days/week (goal at
least 150 min/week). Greater activity levels of at least
1 h/day of moderate (walking) or 30 min/day of vigorous
(jogging) activity may be needed to achieve successful long-term
weight loss. (E)
- Drug
therapy for obesity and surgery to induce weight loss may
be appropriate in selected patients. (E)
- Nonnutritive
sweeteners are safe when consumed within the acceptable
daily intake levels established by the Food and Drug Administration
(FDA). (A)
- If
adults with diabetes choose to use alcohol, daily intake
should be limited to a moderate amount (one drink per day
or less for adult women and two drinks per day or less for
adult men); one drink is defined as 12 oz beer, 5 oz wine,
or 1.5 oz distilled spirits. (A)
- Routine
supplementation with antioxidants, such as vitamins E and
C and ß-carotene, is not advised because of lack of
evidence of efficacy and concern related to long-term safety.
(A)
- Benefit
from chromium supplementation in people with diabetes or
obesity has not been conclusively demonstrated and, therefore,
cannot be recommended. (E)
MNT
is an integral component of diabetes prevention, management,
and self-management education. In addition to its role in
preventing and controlling diabetes, the ADA recognizes the
importance of nutrition as an essential component of an overall
healthy lifestyle. These guidelines are based on principles
of good nutrition for the overall population from the 2005
Dietary Guidelines and the RDAs from the Institute of Medicine
of the National Academies of Sciences. A review of the evidence
and detailed information can be found in the 2002 ADA technical
review on this topic and the 2004 ADA Statements regarding
dietary carbohydrate and weight management.
Goal
of MNT that applies to individuals with pre-diabetes:
- Decrease
the risk of diabetes and CVD by promoting physical activity
and healthy food choices that result in moderate weight
loss that is maintained or, at a minimum, prevents weight
gain.
Goal
of MNT that applies to all individuals with diabetes:
- Prevent
and treat the chronic complications of diabetes by attaining
and maintaining optimal metabolic outcomes, including blood
glucose and A1C level, LDL and HDL cholesterol and triglyceride
levels, blood pressure, and body weight (Table 6).
Achieving
nutrition-related goals requires a coordinated team effort
that includes the active involvement of the person with pre-diabetes
or diabetes. Because of the complexity of nutrition issues,
it is recommended that a registered dietitian who is knowledgeable
and skilled in implementing nutrition therapy into diabetes
management and education be the team member who provides MNT.
However, it is essential that all team members are knowledgeable
about nutrition therapy and are supportive of the person with
diabetes who needs to make lifestyle changes.
MNT
involves a nutrition assessment to evaluate the patients
food intake, metabolic status, lifestyle, readiness to make
changes, goal setting, dietary instruction, and evaluation.
To facilitate adherence, the plan should be individualized
and take into account individual cultural, lifestyle, and
financial considerations. Monitoring of glucose and A1C, lipids,
blood pressure, and renal status is essential to evaluate
nutrition-related outcomes. If goals are not met (Table 6),
changes must be made in the overall diabetes care and management
plan.
Weight
management
Overweight
and obesity are strongly linked to the development of type
2 diabetes and can complicate its management. Obesity is also
an independent risk factor for hypertension and dyslipidemia
as well as CVD, which is the major cause of death in those
with diabetes. Moderate weight loss improves glycemic control,
reduces CVD risk, and can prevent the development of type
2 diabetes in those with pre-diabetes. Therefore, weight loss
is an important therapeutic strategy in all overweight or
obese individuals who have type 2 diabetes or are at risk
for developing diabetes. The primary approach for achieving
weight loss, in the vast majority of cases, is therapeutic
lifestyle change, which includes a reduction in energy intake
and an increase in physical activity. A moderate decrease
in caloric balance (5001,000 kcal/day) will result in
a slow but progressive weight loss (12 lb/week). For
most patients, weight loss diets should supply at least 1,0001,200
kcal/day for women and 1,2001,600 kcal/day for men.
In
selected patients, drug therapy to achieve weight loss as
an adjunct to lifestyle change may be appropriate. However,
it is important to note that regain of weight commonly occurs
on discontinuation of medication. In patients with severe/morbid
obesity, surgical options, such as gastric bypass and gastroplasty,
may be appropriate and allow significant improvement in glycemic
control with reduction or discontinuation of medications.
It is important to fully evaluate the patient for existing
or risk for CVD and improve glycemic control preoperatively
in order to decrease the risk of complications. It is important
to counsel patients on the risks of surgery, including mortality,
depression, hypoglycemia, nutritional deficiencies, osteoporosis,
and weight regain over the long term. Very little data are
currently available on the long-term consequences of surgery
for weight loss in people with diabetes. The potential benefits
should be weighed against short- and long-term risks.
Physical
activity is an important component of a comprehensive weight-management
program. Regular moderate-intensity physical activity enhances
long-term weight maintenance. Regular activity also improves
insulin sensitivity, glycemic control, and selected risk factors
for CVD (i.e., hypertension and dyslipidemia), and increased
aerobic fitness decreases the risk of coronary heart disease
(CHD). Initial physical activity recommendations should be
modest, based on the patients willingness and ability,
gradually increasing the duration and frequency to 3045
min of moderate aerobic activity, 35 days/week, when
possible. Greater activity levels of at least 1 h/day of moderate
(walking) or 30 min/day of vigorous (jogging) activity may
be needed to achieve successful long-term weight loss.
Dietary
carbohydrate
Regulation
of blood glucose to achieve near-normal levels is a primary
goal in the management of diabetes, and thus, dietary techniques
that limit hyperglycemia following a meal are important in
limiting the complications of diabetes. Both the amount (grams)
and type of carbohydrate in a food influence blood glucose
level. The total amount of carbohydrate consumed is a strong
predictor of glycemic response, and thus, monitoring total
grams of carbohydrate, whether by use of exchanges or carbohydrate
counting, remains a key strategy in achieving glycemic control.
A recent analysis of the randomized controlled trials that
have examined the efficacy of the glycemic index (a measure
of the effect of type of carbohydrate) on overall blood glucose
control indicates that the use of this technique may provide
an additional benefit over that observed when total carbohydrate
is considered alone.
Low-carbohydrate
diets are not recommended in the management of diabetes. Although
dietary carbohydrate is the major contributor to postprandial
glucose concentration, it is an important source of energy,
water-soluble vitamins and minerals, and fiber. Thus, in agreement
with the National Academy of SciencesFood and Nutrition
Board, a recommended range of carbohydrate intake is 4565%
of total calories. In addition, because the brain and central
nervous system have an absolute requirement for glucose as
an energy source, restricting total carbohydrate to <130
g/day is not recommended.
Dietary
protein
In
the U.S., mean protein intake from foods (not including supplements)
accounts for 1520% of average energy intake, is fairly
consistent across all ages from childhood to old age, and
appears to be similar in individuals with diabetes. The dietary
reference intake (DRI)-acceptable macronutrient distribution
range for protein is 1035% of energy intake and the
RDA is 0.8 g high-quality protein · kg body wt1
· day1.
Dietary intake of protein is similar to that of the general
public in individuals with diabetes and usually does not exceed
20% of energy intake. Intake of protein in this range may
be a risk factor for the development of diabetic nephropathy.
Based on studies in patients with varying stages of nephropathy,
it seems prudent to limit protein intake in those with diabetes
to the RDA (0.8 g/kg), which would be 10% of total calories.
Dietary
fat
Saturated
and trans fatty acids are the principal dietary determinant
of plasma LDL cholesterol, the major risk factor for CVD.
In nondiabetic individuals, reducing saturated and trans fatty
acids and cholesterol intake decreases plasma total and LDL
cholesterol but may also reduce HDL cholesterol. Importantly,
the ratio of LDL to HDL cholesterol is not adversely affected.
Studies in individuals with diabetes demonstrating the effects
of specific percentages of dietary saturated and trans fatty
acids and specific amounts of dietary cholesterol on CVD risk
are not available. However, those with diabetes are considered
to be at similar risk to those with a past history of CVD.
Therefore, because of a lack of specific information, the
goal for dietary fat intake (amount and type) for individuals
with diabetes is the same as for those without diabetes with
a history of CVD. The most recent guidelines from the National
Cholesterol Education Program recommend that total fat be
2535% of total calories and saturated fat <7%. Guidelines
from the American Heart Association also recommend that saturated
fat be <7% in those with diabetes, given their increased
risk of CVD. Intake of trans fat should be minimized.
Optimal
macronutrient mix
For
those individuals seeking guidance regarding macronutrient
distribution, the DRIs may be helpful The DRI report recommends
that to meet the bodys daily nutritional needs while
minimizing risk for chronic diseases, adults (in general,
not specifically those with diabetes) should consume 4565%
of total energy from carbohydrate, 2035% from fat, and
1035% from protein. Although numerous studies have attempted
to identify the optimal combination of macronutrients for
those with diabetes, it is unlikely that any one such combination
of macronutrients exists. The best mix of carbohydrate, protein,
and fat appears to vary depending on individual circumstances.
Fiber
Similar
to the general population, people with diabetes are encouraged
to choose a variety of fiber-containing foods, such as legumes,
fiber-rich cereals ( 5 g fiber/serving), as well as fruits,
vegetables, and whole-grain products because they provide
vitamins, minerals, fiber, and other substances important
for good health.
Reduced
calorie sweeteners
Reduced
calorie sweeteners approved by the FDA include sugar alcohols
(erythritol, hydrogenated starch hydrolysates, isomalt, lactitol,
maltitol, mannitol, sorbitol, and xylitol) and tagatose. Studies
using subjects with and without diabetes have shown that sugar
alcohols produce a lower postprandial glucose response than
sucrose or glucose and have lower available energy. Sugar
alcohols contain, on average, 2 calories/gram (one-half the
calories of other sweeteners such as sucrose). With foods
containing sugar alcohols, subtraction of one-half of sugar
alcohol grams from total carbohydrate grams is appropriate,
particularly when using the carbohydrate counting method for
meal planning. There is no evidence that the amounts of sugar
alcohol likely to be consumed will result in significant reduction
in energy intake or long-term improvement in glycemia. The
use of sugar alcohols appears to be safe.
The
FDA has approved five nonnutritive sweeteners for use in the
U.S.: acesulfame potassium, aspartame, neotame, saccharin,
and sucralose. All have undergone rigorous scrutiny and have
been shown to be safe when consumed by the public, including
people with diabetes and women who are pregnant.
Antioxidants
Since
diabetes may be a state of increased oxidative stress, there
has been interest in prescribing antioxidant vitamins to individuals
with diabetes. While observational studies have shown a correlation
between dietary or supplemental consumption of antioxidants
and a variety of clinical outcomes such as prevention of disease
states, large placebo-controlled clinical trials have failed
to show a benefit and, in some instances, have suggested adverse
effects.
Chromium
Several
small studies have suggested a role for chromium supplementation
in the management of glucose intolerance, body weight, GDM,
and corticosteroid-induced diabetes. Also, placebo-controlled
studies conducted in China found that chromium supplementation
had beneficial effects on glycemia, although it is important
to note that the study population in China may have had marginal
baseline chromium status. A recent FDA statement indicated
that there is insufficient evidence to support any of the
proposed health claims for chromium supplementation. The FDA
concluded that although a small study suggested that chromium
picolinate may reduce the risk of insulin resistance, the
existence of a relationship between chromium picolinate and
either insulin resistance or type 2 diabetes was highly uncertain
(see "chromium picolinate and insulin resistance"
at www.cfsan.fda.gov/ dms/qhccr.html). In addition, a meta-analysis
of randomized controlled trials suggested no benefit of chromium
picolinate supplementation in reducing body weight.
Alcohol
For
individuals with diabetes, the same precautions apply regarding
the use of alcohol that apply to the general population. If
individuals choose to use alcohol, alcohol-containing beverages
should be limited to a moderate amount (less than one drink
per day for adult women and less than two drinks per day for
adult men). One alcohol containing beverage is defined as
12 oz beer, 5 oz wine, or 1.5 oz distilled spirits. Each contains
15 g alcohol.
E.
DSME
Recommendations
- People
with diabetes should receive DSME according to national
standards when their diabetes is diagnosed and as needed
thereafter. (B)
- DSME
should be provided by health care providers who are qualified
to provide that DSME based on their professional training
and continuing education. (E)
- DSME
should address psychosocial issues, since emotional well-being
is strongly associated with positive diabetes outcomes.
(C)
- DSME
should be reimbursed by third-party payors. (E)
DSME
is an essential element of diabetes care, and National Standards
for DSME are based on evidence for its benefits. Education
helps people with diabetes initiate effective self-care when
they are first diagnosed. Ongoing DSME also helps people with
diabetes maintain effective self-management as their diabetes
presents new challenges and treatment advances become available.
DSME helps patients optimize metabolic control, prevent and
manage complications, and maximize quality of life, in a cost-effective
manner.
Evidence
for the benefits of DSME
Since
the 1990s, there has been a shift from a didactic approach
with DSME focusing on providing information to a skill-based
approach that focuses on helping those with diabetes make
informed self-management choices. Several studies have found
that DSME is associated with improved diabetes knowledge,
improved self-care behavior, improved clinical outcomes such
as lower A1C, lower self-reported weight, and improved quality
of life. Better outcomes were reported for DSME that were
longer and included follow-up support, were tailored to individual
needs and preferences , and addressed psychosocial issues.
The
national standards for DSME
ADA-recognized
DSME programs have staff that includes at least a registered
nurse and a registered dietitian; these staff must be certified
diabetes educators or have recent experience in diabetes education
and management. The curriculum of ADA-recognized DSME programs
must cover all areas of diabetes management, with the assessed
needs of the individual determining which areas are addressed.
All ADA-recognized DSME programs utilize a process of continuous
quality improvement to evaluate the effectiveness of the DSME
provided and to identify opportunities for improvement.
Reimbursement
for DSME
DSME
is reimbursed as part of the Medicare program as overseen
by the Center for Medicare and Medicaid Services (CMS) (http://www.hcfa.gov/coverage).
F.
Physical activity
Recommendations
- To
improve glycemic control, assist with weight maintenance,
and reduce risk of CVD, at least 150 min/week of moderate-intensity
aerobic physical activity (5070% of maximum heart
rate) is recommended and/or at least 90 min/week of vigorous
aerobic exercise (>70% of maximum heart rate). The physical
activity should be distributed over at least 3 days/week
and with no more than 2 consecutive days without physical
activity. (A)
- In
the absence of contraindications, people with type 2 diabetes
should be encouraged to perform resistance exercise three
times a week, targeting all major muscle groups, progressing
to three sets of 810 repetitions at a weight that
cannot be lifted more than 810 times. (A)
Indications
for graded exercise test with electrocardiogram monitoring
- A
graded exercise test with electrocardiogram (ECG) monitoring
should be seriously considered before undertaking aerobic
physical activity with intensity exceeding the demands of
everyday living (more intense than brisk walking) in previously
sedentary diabetic individuals whose 10-year risk of a coronary
event is likely to be 10%.
ADA
technical reviews on exercise in patients with diabetes have
summarized the value of exercise in the diabetes management
plan. Regular exercise has been shown to improve blood glucose
control, reduce cardiovascular risk factors, contribute to
weight loss, and improve well-being. Furthermore, regular
exercise may prevent type 2 diabetes in high-risk individuals.
Definitions
The
following definitions are based on those outlined in "Physical
Activity and Health," the 1996 report of the Surgeon
General. Physical activity is defined as bodily movement produced
by the contraction of skeletal muscle that requires energy
expenditure in excess of resting energy expenditure. Exercise
is a subset of physical activity: planned, structured, and
repetitive bodily movement performed to improve or maintain
one or more components of physical fitness. Aerobic exercise
consists of rhythmic, repeated, and continuous movements of
the same large muscle groups for at least 10 min at a time.
Examples include walking, bicycling, jogging, swimming, water
aerobics, and many sports. Resistance exercise consists of
activities that use muscular strength to move a weight or
work against a resistive load. Examples include weight lifting
and exercises using weight machines.
Effects
of structured exercise interventions on glycemic control and
body weight in type 2 diabetes
Boulé
et al. undertook a systematic review and meta-analysis on
the effects of structured exercise interventions in clinical
trials of duration 8 weeks on HbA1c and body mass in people
with type 2 diabetes. Twelve aerobic training studies and
two resistance training studies were included (totaling 504
subjects), and the results were pooled using standard meta-analytic
statistical methods. Postintervention HbA1c was significantly
lower in exercise than control groups. Metaregression confirmed
that the beneficial effect of exercise on HbA1c was independent
of any effect on body weight. Therefore, structured exercise
programs had a statistically and clinically significant beneficial
effect on glycemic control, and this effect was not mediated
primarily by weight loss.
Boulé
et al. later undertook a meta-analysis of the interrelationships
among exercise intensity, exercise volume, change in cardiorespiratory
fitness, and change in HbA1c. This meta-analysis provides
support for higher-intensity aerobic exercise in people with
type 2 diabetes as a means of improving HbA1c. These results
would provide support for encouraging type 2 diabetic individuals
who are already exercising at moderate intensity to consider
increasing the intensity of their exercise in order to obtain
additional benefits in both aerobic fitness and glycemic control.
Frequency
of exercise
The
U.S. Surgeon Generals report recommended that most people
accumulate 30 min of moderate intensity activity on most,
ideally all, days of the week. The American College of Sports
Medicine now recommends resistance training be included in
fitness programs for adults with type 2 diabetes. Resistance
exercise improves insulin sensitivity to about the same extent
as aerobic exercise. Two clinical trials published in 2002
provided strong evidence for the value of resistance training
in type 2 diabetes.
Evaluation
of the diabetic patient before recommending an exercise program
Before
beginning a program of physical activity more vigorous than
brisk walking, people with diabetes should be assessed for
conditions that might be associated with increased likelihood
of CVD or that might contraindicate certain types of exercise
or predispose to injury, such as uncontrolled hypertension,
severe autonomic neuropathy, severe peripheral neuropathy,
and preproliferative or proliferative retinopathy or macular
edema. The patients age and previous physical activity
level should be considered.
A
recent systematic review for the U.S. Preventive Services
Task Force came to the conclusion that stress tests should
usually not be recommended to detect ischemia in asymptomatic
individuals at low CAD risk (<10% risk of a cardiac event
over 10 years) because the risks of subsequent invasive testing
triggered by false-positive tests outweighed the expected
benefits from detection of previously unsuspected ischemia.
Exercise
in the presence of nonoptimal glycemic control
Hyperglycemia.
When
people with type 1 diabetes are deprived of insulin for 1248
h and ketotic, exercise can worsen hyperglycemia and ketosis.
Vigorous activity should probably be avoided in the presence
of ketosis. Therefore, provided the patient feels well and
urine and/or blood ketones are negative, it is not necessary
to postpone exercise based simply on hyperglycemia.
Hypoglycemia
In
individuals taking insulin and/or insulin secretagogues, physical
activity can cause hypoglycemia if medication dose or carbohydrate
consumption is not altered. Hypoglycemia would be rare in
diabetic individuals who are not treated with insulin or insulin
secretagogues. Added carbohydrate should be ingested if pre-exercise
glucose levels are <100 mg/dl (5.6 mmol/l). We agree with
this recommendation for individuals on insulin and/or an insulin
secretagogue. However, the revised guidelines clarify that
supplementary carbohydrate is generally not necessary for
individuals treated only with diet, metformin, -glucosidase
inhibitors and/or TZDs without insulin or a secretagogue.
Exercise
in the presence of specific long-term complications of diabetes
Retinopathy
In
the presence of proliferative diabetic retinopathy (PDR) or
severe nonproliferative diabetic retinopathy (NPDR), vigorous
aerobic or resistance exercise may be contraindicated because
of the risk of triggering vitreous hemorrhage or retinal detachment.
Peripheral
neuropathy
Decreased
pain sensation in the extremities would result in increased
risk of skin breakdown and infection and of Charcot joint
destruction. Therefore, in the presence of severe peripheral
neuropathy, it may be best to encourage nonweight-bearing
activities such as swimming, bicycling, or arm exercises.
Autonomic
neuropathy
Autonomic
neuropathy can increase the risk of exercise-induced injury
by decreasing cardiac responsiveness to exercise, postural
hypotension, impaired thermoregulation due to impaired skin
blood flow and sweating, impaired night vision due to impaired
papillary reaction, impaired thirst increasing risk of dehydration,
and gastroparesis with unpredictable food delivery. Autonomic
neuropathy is also strongly associated with CVD in people
with diabetes. People with diabetic autonomic neuropathy should
definitely undergo cardiac investigation before beginning
physical activity more intense than they are accustomed to.
Microalbuminuria
and nephropathy
Physical
activity can acutely increase urinary protein excretion. There
is no evidence from clinical trials or cohort studies demonstrating
that vigorous exercise increases the rate of progression of
diabetic kidney disease. There may be no need for any specific
exercise restrictions for people with diabetic kidney disease.
G.
Psychosocial assessment and care
Recommendations
- Preliminary
assessment of psychological and social status should be
included as part of the medical management of diabetes.
(E)
- Psychosocial
screening should include but is not limited to attitudes
about the illness, expectations for medical management and
outcomes, affect/mood, general and diabetes-related quality
of life, resources (financial, social, and emotional), and
psychiatric history. (E)
- Screening
for psychosocial problems such as depression, eating disorders,
and cognitive impairment is needed when adherence to the
medical regimen is poor. (E)
- It
is preferable to incorporate psychological treatment into
routine care rather than wait for identification of a specific
problem or deterioration in psychological status. (E)
Psychological
and social state can impact the patients ability to
carry out diabetes care tasks. As a result, health status
may be compromised. Family conflict around diabetes care tasks
is also common and may interfere with treatment outcomes.
There are opportunities for the clinician to assess psychosocial
status in a timely and efficient manner so that referral for
appropriate services can be accomplished.
Key
opportunities for screening of psychosocial status occur at
diagnosis, during regularly scheduled management visits, during
hospitalizations, at discovery of complications, or at the
discretion of the clinician when problems in glucose control,
quality of life, or adherence are identified. Patients are
likely to exhibit psychological vulnerability at diagnosis
and when their medical status changes: the end of the honeymoon
period, when the need for intensified treatment is evident
and when complications are discovered.
Psychosocial
screening should include but is not limited to attitudes about
the illness, expectations for medical management and outcomes,
affect/mood, general and diabetes-related quality of life,
resources (financial, social, and emotional), and psychiatric
history. Particular attention needs to be paid to gross noncompliance
with medical regimen (due to self or others), depression with
the possibility of self-harm, indications of an eating disorder
or a problem that appears to be organic in origin, and cognitive
functioning that significantly impairs judgment. In these
cases, immediate referral for further evaluation by a mental
health specialist familiar with diabetes management should
occur. Behavioral assessment of management skills is also
recommended.
It
is preferable to incorporate psychological treatment into
routine care rather than waiting for identification of a specific
problem or deterioration in psychological status. Screening
tools can facilitate this goal, and although the clinician
may not feel qualified to treat psychological problems, utilizing
the patient-provider relationship as a foundation for further
treatment can increase the likelihood that the patient will
accept referral for other services. It is important to establish
that emotional well-being is part of diabetes management.
H.
Referral for diabetes management
For
a variety of reasons, some people with diabetes and their
health care providers do not achieve the desired goals of
treatment (Table 6). Intensification of the treatment regimenis
suggested and includes identification (or assessment) of barriers
to adherence, culturally appropriate and enhanced DSME, comanagement
with a diabetes team, change in pharmacological therapy, initiation
of or increase in SMBG, more frequent contact with the patient,
and referral to an endocrinologist.
I.
Intercurrent illness
The
stress of illness, trauma, and/or surgery frequently aggravates
glycemic control and may precipitate diabetic ketoacidosis
(DKA) or nonketotic hyperosmolar state. Any condition leading
to deterioration in glycemic control necessitates more frequent
monitoring of blood glucose and urine or blood ketones. A
vomiting illness accompanied by ketosis may indicate DKA,
a life-threatening condition that requires immediate medical
care to prevent complications and death; the possibility of
DKA should always be considered. Marked hyperglycemia requires
temporary adjustment of the treatment program and, if accompanied
by ketosis, frequent interaction with the diabetes care team.
The patient treated with oral glucose-lowering agents or MNT
alone may temporarily require insulin. Adequate fluid and
caloric intake must be assured. Infection or dehydration is
more likely to necessitate hospitalization of the person with
diabetes than the person without diabetes. The hospitalized
patient should be treated by a physician with expertise in
the management of diabetes, and recent studies suggest that
achieving very stringent glycemic control may reduce mortality
in the immediate postmyocardial infarction period. Aggressive
glycemic management with insulin may reduce morbidity in patients
with severe acute illness.
For
further information on management of patients in the hospital
with DKA or nonketotic hyperosmolar state, refer to the ADA
position statement.
J.
Hypoglycemia
Recommendations
- Glucose
(1520 g) is the preferred treatment for hypoglycemia,
although any form of carbohydrate that contains glucose
may be used, and treatment effects should be apparent in
15 min. (E)
- Treatment
effects on hypoglycemia may only be temporarily corrected.
Therefore, plasma glucose should be tested again in 15 min
as additional treatment may be necessary. (B)
- Glucagon
should be prescribed for all patients at significant risk
of severe hypoglycemia and does not require a health care
professional for its administration. (E)
Hypoglycemia,
especially in insulin-treated patients, is the leading limiting
factor in the glycemic management of type 1 and type 2 diabetes.
Treatment of hypoglycemia (plasma glucose <70 mg/dl) requires
ingestion of glucose- or carbohydrate-containing foods. The
acute glycemic response correlates better with the glucose
content than with the carbohydrate content of the food. Although
pure glucose may be the preferred treatment, any form of carbohydrate
that contains glucose will raise blood glucose. Adding protein
to carbohydrate does not affect the glycemic response and
does not prevent subsequent hypoglycemia. Adding fat, however,
may retard and then prolong the acute glycemic response.
Rare
situations of severe hypoglycemia (where the individual requires
the assistance of another person and cannot be treated with
oral carbohydrate) should be treated using emergency glucagon
kits, which require a prescription. Those in close contact
with, or having custodial care of, people with diabetes, such
as family members, roommates, school personnel, child care
providers, correctional institution staff, and coworkers,
should be instructed in use of such kits. An individual does
not need to be a health care professional to safely administer
glucagon. Care should be taken to ensure that unexpired glucagon
kits are available.
K.
Immunization
Recommendations
- Annually
provide an influenza vaccine to all diabetic patients 6
months of age. (C)
- Provide
at least one lifetime pneumococcal vaccine for adults with
diabetes. A one-time revaccination is recommended for individuals
>64 years of age previously immunized when they were
<65 years of age if the vaccine was administered >5
years ago. Other indications for repeat vaccination include
nephrotic syndrome, chronic renal disease, and other immunocompromised
states, such as after transplantation. (C)
Influenza
and pneumonia are common, preventable infectious diseases
associated with high mortality and morbidity in the elderly
and in people with chronic diseases. There are limited studies
reporting the morbidity and mortality of influenza and pneumococcal
pneumonia specifically in people with diabetes. Observational
studies of patients with a variety of chronic illnesses, including
diabetes, show that these conditions are associated with an
increase in hospitalizations for influenza and its complications.
Based on a case-control series, influenza vaccine has been
shown to reduce diabetes-related hospital admission by as
much as 79% during flu epidemics. People with diabetes may
be at increased risk of the bacteremic form of pneumococcal
infection and have been reported to have a high risk of nosocomial
bacteremia, which has a mortality rate as high as 50%.
Safe
and effective vaccines are available that can greatly reduce
the risk of serious complications from these diseases. There
is sufficient evidence to support that people with diabetes
have appropriate serologic and clinical responses to these
vaccinations. The Centers for Disease Controls Advisory
Committee on Immunization Practices recommends influenza and
pneumococcal vaccines for all individuals >65 years of
age, as well as for all individuals of any age with diabetes.
For
a complete discussion on the prevention of influenza and pneumococcal
disease in people with diabetes, consult the technical review
and position statement on this subject.
|
VI. PREVENTION AND MANAGEMENT OF DIABETES COMPLICATIONS
|
A.
CVD
CVD
is the major cause of mortality for individuals with diabetes.
It is also a major contributor to morbidity and direct and
indirect costs of diabetes. Type 2 diabetes is an independent
risk factor for macrovascular disease, and its common coexisting
conditions (e.g., hypertension and dyslipidemia) are also
risk factors.
Studies
have shown the efficacy of reducing cardiovascular risk factors
in preventing or slowing CVD. Evidence is summarized in the
following sections and reviewed in detail in the ADA technical
reviews on hypertension, dyslipidemia , aspirin therapy ,
and smoking cessation and the consensus statement on CHD in
people with diabetes. Emphasis should be placed on reducing
cardiovascular risk factors, when possible, and clinicians
should be alert for signs and symptoms of atherosclerosis.
1.
Hypertension/blood pressure control
Recommendations
Screening
and diagnosis
- Blood
pressure should be measured at every routine diabetes visit.
Patients found to have systolic blood pressure 130 mmHg
or diastolic blood pressure 80 mmHg should have blood pressure
confirmed on a separate day. (C)
Goals
- Patients
with diabetes should be treated to a systolic blood pressure
<130 mmHg. (C)
- Patients
with diabetes should be treated to a diastolic blood pressure
<80 mmHg. (B)
Treatment
- Patients
with hypertension (systolic blood pressure 140 or diastolic
blood pressure 90 mmHg) should receive drug therapy in addition
to lifestyle and behavioral therapy. (A)
- Multiple
drug therapy (two or more agents at proper doses) is generally
required to achieve blood pressure targets. (B)
- Patients
with a systolic blood pressure of 130139 mmHg or a
diastolic blood pressure of 8089 mmHg should be given
lifestyle and behavioral therapy alone for a maximum of
3 months and then, if targets are not achieved, in addition,
be treated with pharmacological agents that block the renin-angiotensin
system. (E)
- Initial
drug therapy for those with a blood pressure >140/90
mmHg should be with a drug class demonstrated to reduce
CVD events in patients with diabetes (ACE inhibitors, ARBs,
ß-blockers, diuretics, and calcium channel blockers).
(A)
- All
patients with diabetes and hypertension should be treated
with a regimen that includes either an ACE inhibitor or
an ARB. If one class is not tolerated, the other should
be substituted. If needed to achieve blood pressure targets,
a thiazide diuretic should be added. (E)
- If
ACE inhibitors, ARBs, or diuretics are used, monitor renal
function and serum potassium levels. (E)
In patients with type 1 diabetes,
with hypertension and any degree of albuminuria, ACE inhibitors
have been shown to delay the progression
of nephropathy. (A)
In patients with type 2 diabetes,
hypertension, and microalbuminuria, ACE inhibitors and ARBs
have been shown to delay the progression to macroalbuminuria.
(A)
In those with type 2 diabetes,
hypertension, macroalbuminuria, and renal insufficiency,
ARBs have been shown to delay the progression of nephropathy.
(A)
- In
pregnant patients with diabetes and chronic hypertension,
blood pressure target goals of 110129/6579 mmHg
are suggested in the interest of long-term maternal health
and minimizing impaired fetal growth. ACE inhibitors and
ARBs are contraindicated during pregnancy. (E)
- In
elderly hypertensive patients, blood pressure should be
lowered gradually to avoid complications. (E)
- Patients
not achieving target blood pressure despite multiple drug
therapy should be referred to a physician experienced in
the care of patients with hypertension. (E)
- Orthostatic
measurement of blood pressure should be performed in people
with diabetes and hypertension when clinically indicated.
(E)
Hypertension
(blood pressure 140/90 mmHg) is a common comorbidity of diabetes,
affecting the majority of people with diabetes, depending
on type of diabetes, age, obesity, and ethnicity. Hypertension
is also a major risk factor for CVD and microvascular complications
such as retinopathy and nephropathy. In type 1 diabetes, hypertension
is often the result of underlying nephropathy. In type 2 diabetes,
hypertension may be present as part of the metabolic syndrome
(i.e., obesity, hyperglycemia and dyslipidemia) that is accompanied
by high rates of CVD.
Randomized
clinical trials have demonstrated the benefit (reduction of
CHD events, stroke, and nephropathy) of lowering blood pressure
to <140 mmHg systolic and <80 mmHg diastolic in individuals
with diabetes. Epidemiologic analyses show that blood pressures
>115/75 mmHg are associated with increased cardiovascular
event rates and mortality in individuals with diabetes. Therefore,
a target blood pressure goal of <130/80 mmHg is reasonable
if it can be safely achieved.
Although
there are no well-controlled studies of diet and exercise
in the treatment of hypertension in individuals with diabetes,
reducing sodium intake and body weight (when indicated), increasing
consumption of fruits, vegetables, and low-fat dairy products,
avoiding excessive alcohol consumption, and increasing activity
levels have been shown to be effective in reducing blood pressure
in nondiabetic individuals. These nonpharmacological strategies
may also positively affect glycemia and lipid control. Their
effects on cardiovascular events have not been well measured.
Lowering
of blood pressure with regimens based on antihypertensive
drugs, including ACE inhibitors, angiotensin receptor blockers
(ARBs), ß-blockers, diuretics, and calcium channel blockers,
has been shown to be effective in lowering cardiovascular
events. Several studies suggest that ACE inhibitors may be
superior to dihydropyridine calcium channel blockers (DCCBs)
in reducing cardiovascular events. Additionally, in people
with diabetic nephropathy indicate that ARBs may be superior
to DCCBs for reducing heart failure but not overall cardiovascular
events. Conversely, in the recently completed International
Verapamil Study (INVEST) of >22,000 people with CAD and
hypertension, the non-DCCB verapamil demonstrated a similar
reduction in cardiovascular mortality to a ß-blocker.
Moreover, this relationship held true in the diabetic subgroup.
ACE
inhibitors have been shown to improve cardiovascular outcomes
in highcardiovascular risk patients with or without
hypertension. In patients with congestive heart failure (CHF),
the addition of ARBs to either ACE inhibitors or other therapies
reduces the risk of cardiovascular death or hospitalization
for heart failure. In one study, an ARB was superior to a
ß-blocker as a therapy to improve cardiovascular outcomes
in a subset of diabetic patients with hypertension and left
ventricular hypertrophy. The compelling effect of ACE inhibitors
or ARBs in patients with albuminuria or renal insufficiency
provide additional rationale for use of these agents (see
section VI, B below).
The
Antihypertensive and Lipid-Lowering Treatment to Prevent Heart
Attack Trial (ALLHAT), a large randomized trial of different
initial blood pressure pharmacological therapies, found no
large differences between initial therapy with a chlorthalidone,
amlodipine and lisinopril. Diuretics appeared slightly more
effective than other agents, particularly for reducing heart
failure. The -blocker arm of the ALLHAT was terminated after
interim analysis showed that doxazosin was substantially less
effective in reducing CHF than diuretic therapy.
Before
beginning treatment, patients with elevated blood pressure
should have their blood pressure reexamined within 1 month
to confirm the presence of hypertension. Systolic blood pressure
160 mmHg or diastolic blood pressure 100 mmHg, however, mandates
that immediate pharmacological therapy be initiated. Patients
with hypertension should be seen as often as needed until
the recommended blood pressure goal is obtained and then seen
as necessary. In these patients, other cardiovascular risk
factors, including obesity, hyperlipidemia, smoking, presence
of microalbuminuria (assessed before initiation of treatment),
and glycemic control, should be carefully assessed and treated.
Many patients will require three or more drugs to reach target
goals.
During
pregnancy in diabetic women with chronic hypertension, target
blood pressure goals of systolic blood pressure 110129
mmHg and diastolic blood pressure 6579 mmHg are reasonable,
as they may contribute to long-term maternal health. Lower
blood pressure levels may be associated with impaired fetal
growth. During pregnancy treatment with ACE inhibitors and
ARBs is contraindicated, since they are likely to cause fetal
damage. Antihypertensive drugs known to be effective and safe
in pregnancy include methyldopa, labetalol, diltiazem, clonidine,
and prazosin. Chronic diuretic use during pregnancy has been
associated with restricted maternal plasma volume, which might
reduce uteroplacental perfusion.
2.
Dyslipidemia/lipid management
Recommendations
Screening
- In
adult patients, test for lipid disorders at least annually
and more often if needed to achieve goals. In adults with
low-risk lipid values (LDL <100 mg/dl, HDL >50 mg/dl,
and triglycerides <150 mg/dl), lipid assessments may
be repeated every 2 years. (E)
Treatment
recommendations and goals
- Lifestyle
modification focusing on the reduction of saturated fat
and cholesterol intake, weight loss (if indicated), and
increased physical activity has been shown to improve the
lipid profile in patients with diabetes. (A)
- In
individuals without overt CVD
The primary goal is an LDL <100 mg/dl (2.6 mmol/l). (A)
For those over the age of 40 years,
statin therapy to achieve an LDL reduction of 3040%
regardless of baseline LDL levels is
recommended. (A)
For those under the age of 40 years
but at increased risk due to other cardiovascular risk factors
who do not achieve lipid goals with lifestyle
modifications alone, the addition of pharmacological therapy
is appropriate. (C)
- In
individuals with overt CVD
All patients should be treated
with a statin to achieve an LDL reduction of 3040%.
(A)
A lower LDL cholesterol goal of
<70 mg/dl (1.8 mmol/l), using a high dose of a statin,
is an option. (B)
- Lower
triglycerides to <150 mg/dl (1.7 mmol/l) and raise HDL
cholesterol to >40 mg/dl (1.15 mmol/l). In women, an
HDL goal 10 mg/dl higher (>50 mg/dl) should be considered.
(C)
- Lowering
triglycerides and increasing HDL cholesterol with a fibrate
is associated with a reduction in cardiovascular events
in patients with clinical CVD, low HDL, and near-normal
levels of LDL. (A)
- Combination
therapy using statins and other lipid-lowering agents may
be necessary to achieve lipid targets but has not been evaluated
in outcomes studies for either CVD event reduction or safety.
(E)
- Statin
therapy is contraindicated in pregnancy. (E)
Patients
with type 2 diabetes have an increased prevalence of lipid
abnormalities that contributes to higher rates of CVD. Lipid
management aimed at lowering LDL cholesterol, raising HDL
cholesterol, and lowering triglycerides has been shown to
reduce macrovascular disease and mortality in patients with
type 2 diabetes, particularly in those who have had prior
cardiovascular events. In studies using HMG (hydroxymethylglutaryl)-CoA
reductase inhibitors (statins), patients with diabetes achieved
significant reductions in coronary and cerebrovascular events.
In two studies using the fibric acid derivative gemfibrozil,
reductions in cardiovascular end points were also achieved.
Target
lipid levels are shown in Table
6. Lifestyle intervention, including MNT, increased physical
activity, weight loss, and smoking cessation, should allow
some patients to reach these lipid levels. Nutrition intervention
should be tailored according to each patients age, type
of diabetes, pharmacological treatment, lipid levels, and
other medical conditions and should focus on the reduction
of saturated fat, cholesterol, and transunsaturated fat intake.
Glycemic control can also beneficially modify plasma lipid
levels. Particularly in patients with very high triglycerides
and poor glycemic control, glucose lowering may be necessary
to control hypertriglyceridemia. Pharmacological treatment
is indicated if there is an inadequate response to lifestyle
modifications and improved glucose control. However, in patients
with clinical CVD and LDL >100 mg/dl, pharmacological therapy
should be initiated at the same time that lifestyle intervention
is started. In patients with diabetes aged <40 years, similar
consideration for LDL-lowering therapy should be given if
they have increased cardiovascular risk (e.g., additional
cardiovascular risk factors or long duration of diabetes).
Very little clinical trial data exist in patients in this
age-group.
The
first priority of pharmacological therapy is to lower LDL
cholesterol to a target goal of <100 mg/dl (2.60 mmol/l)
or therapy to achieve a reduction in LDL of 3040%. For
LDL lowering, statins are the drugs of choice. Other drugs
that lower LDL include nicotinic acid, ezetimbe, bile acid
sequestrants, and fenofibrate.
The
Heart Protection Study demonstrated that in individuals with
diabetes over the age of 40 years with a total cholesterol
>135 mg/dl, LDL reduction of 30% from baseline with the
statin simvastatin was associated with an 25% reduction in
the first event rate for major coronary artery events independent
of baseline LDL, preexisting vascular disease, type or duration
of diabetes, or adequacy of glycemic control. Similarly, in
the Coronary Artery Diabetes Study (CARDS), patients with
type 2 diabetes randomized to 10 mg atorvastatin daily had
a significant reduction in cardiovascular events including
stroke.
Recent
clinical trials in high-risk patients, such as those with
acute coronary syndromes or previous cardiovascular events,
have demonstrated that more aggressive therapy with high doses
of statins to achieve an LDL of <70 mg/dl led to a significant
reduction in further events. The risk of side effects with
high doses of statins is significantly outweighed by the benefits
of such therapy in these high-risk patients. Therefore, a
reduction in LDL to a goal of <70 mg/dl is an option in
very-high-risk patients with overt CVD. The combination of
statins with other lipid-lowering drugs such as ezetimibe
may allow achievement of the LDL goal with a lower dose of
a statin in such patients, but no data are available as to
whether such combination therapy is more effective than a
statin alone in preventing cardiovascular events.
Relatively
little data are available on lipid-lowering therapy in subjects
with type 1 diabetes. In the Heart Protection Study, 600 patients
with type 1 diabetes had a proportionately similar, but not
statistically significant, reduction in risk compared with
patients with type 2 diabetes. Although the data are not definitive,
consideration should be given for similar lipid-lowering therapy
in type 1 diabetic patients as in type 2 diabetic patients,
particularly if they have other cardiovascular risk factors
or features of the metabolic syndrome.
If
the HDL is <40 mg/dl and the LDL is between 100 and 129
mg/dl, a fibric acid derivative or niacin might be used. Niacin
is the most effective drug for raising HDL but can significantly
increase blood glucose at high doses. More recent studies
demonstrate that at modest doses (7502,000 mg/day),
significant benefit with regards to LDL, HDL, and triglyceride
levels are accompanied by only modest changes in glucose that
are generally amenable to adjustment of diabetes therapy.
Combination
therapy, with a statin and a fibrate or statin and niacin,
may be efficacious for patients needing treatment for all
three lipid fractions, but this combination is associated
with an increased risk for abnormal transaminase levels, myositis,
or rhabdomyolysis. The risk of rhabdomyolysis seems to be
lower when statins are combined with fenofibrate than gemfibrozil.
There is also a risk of a rise in plasma creatinine, particularly
with fenofibrate. It is important to note that clinical trials
with fibrates and niacin have demonstrated benefits in patients
who were not on treatment with statins and that there are
no data available on reduction of events with such combinations.
The risks may be greater in patients who are treated with
combinations of these drugs with high doses of statins.
3.
Antiplatelet agents
Recommendations
- Use
aspirin therapy (75162 mg/day) as a secondary prevention
strategy in those with diabetes with a history of CVD. (A)
- Use
aspirin therapy (75162 mg/day) as a primary prevention
strategy in those with:
Type 2 diabetes at increased cardiovascular
risk, including those who are >40 years of age or who
have additional risk factors (family
history of CVD, hypertension,
smoking, dyslipidemia, or albuminuria). (A)
Type 1 diabetes at increased cardiovascular
risk, including those who are >40 years of age or who
have additional risk factors (family
history of CVD, hypertension,
smoking, dyslipidemia, or albuminuria). (C)
- Consider
aspirin therapy in people between the age of 30 and 40 years,
particularly in the presence of other cardiovascular risk
factors. (E)
- Aspirin
therapy should not be recommended for patients under the
age of 21 years because of the increased risk of Reyes
syndrome associated with aspirin use in this population.
People <30 years have not been studied. (E)
- Combination
therapy using other antiplatelet agents such as clopidrogel
in addition to aspirin should be used in patients with severe
and progressive CVD. (C)
- Other
antiplatelet agents may be a reasonable alternative for
high-risk patients with aspirin allergy, bleeding tendency,
receiving anticoagulant therapy, recent gastrointestinal
bleeding, and clinically active hepatic disease who are
not candidates for aspirin therapy. (E)
The
use of aspirin in diabetes is reviewed in detail in the ADA
technical review and position statement on aspirin therapy.
Aspirin has been recommended as a primary and secondary therapy
to prevent cardiovascular events in diabetic and nondiabetic
individuals. One large meta-analysis and several clinical
trials demonstrate the efficacy of using aspirin as a preventive
measure for cardiovascular events, including stroke and myocardial
infarction. Many trials have shown an 30% decrease in myocardial
infarction and a 20% decrease in stroke in a wide range of
patients, including young and middle-aged patients, patients
with and without a history of CVD, males and females, and
patients with hypertension.
Dosages
used in most clinical trials ranged from 75 to 325 mg/day.
There is no evidence to support any specific dose, but using
the lowest possible dosage may help reduce side effects. There
is no evidence for a specific age at which to start aspirin,
but at ages <30 years, aspirin has not been studied.
Clopidogrel
has been demonstrated to reduce CVD rates in diabetic individuals.
Adjunctive therapy in very-high-risk patients or as alternative
therapy in aspirin-intolerant patients should be considered.
4.
Smoking cessation
Recommendations
- Advise
all patients not to smoke. (A)
- Include
smoking cessation counseling and other forms of treatment
as a routine component of diabetes care. (B)
Issues
of smoking in diabetes are reviewed in detail in the ADA technical
review and position statement on smoking cessation. A large
body of evidence from epidemiological, case-control, and cohort
studies provides convincing documentation of the causal link
between cigarette smoking and health risks. Cigarette smoking
contributes to one of every five deaths in the U.S. and is
the most important modifiable cause of premature death. Much
of the prior work documenting the impact of smoking on health
did not separately discuss results on subsets of individuals
with diabetes, suggesting that the identified risks are at
least equivalent to those found in the general population.
Other studies of individuals with diabetes consistently found
a heightened risk of morbidity and premature death associated
with the development of macrovascular complications among
smokers. Smoking is also related to the premature development
of microvascular complications of diabetes and may have a
role in the development of type 2 diabetes.
A
number of large randomized clinical trials have demonstrated
the efficacy and cost-effectiveness of counseling in changing
smoking behavior. Such studies, combined with others specific
to individuals with diabetes, suggest that smoking cessation
counseling is effective in reducing tobacco use.
The
routine and thorough assessment of tobacco use is important
as a means of preventing smoking or encouraging cessation.
Special considerations should include assessment of level
of nicotine dependence, which is associated with difficulty
in quitting and relapse.
5.
CHD screening and treatment
Recommendations
- In
patients >55 years of age, with or without hypertension
but with another cardiovascular risk factor (history of
CVD, dyslipidemia, microalbuminuria, or smoking), an ACE
inhibitor (if not contraindicated) should be considered
to reduce the risk of cardiovascular events. (A)
- In
patients with a prior myocardial infarction or in patients
undergoing major surgery, ß-blockers, in addition,
should be considered to reduce mortality. (A)
- In
asymptomatic patients, consider a risk factor evaluation
to stratify patients by 10-year risk and treat risk factors
accordingly. (B)
- In
patients with treated CHF, metformin use is contraindicated.
The TZDs are associated with fluid retention, and their
use can be complicated by the development of CHF. Caution
in prescribing TZDs in the setting of known CHF or other
heart diseases, as well as in patients with preexisting
edema or concurrent insulin therapy, is required. (C)
CHD
screening and treatment are reviewed in detail in the ADA
consensus statement on CHD in people with diabetes. To identify
the presence of CHD in diabetic patients without clear or
suggestive symptoms of CAD, a risk factorbased approach
to the initial diagnostic evaluation and subsequent follow-up
is recommended. However, a recent study concluded that using
current guidelines fails to detect a significant percentage
of patients with silent ischemia.
At
least annually, cardiovascular risk factors should be assessed.
These risk factors include dyslipidemia, hypertension, smoking,
a positive family history of premature coronary disease, and
the presence of micro- or macroalbuminuria. Abnormal risk
factors should be treated as described elsewhere in these
guidelines. Patients at increased CHD risk should receive
aspirin and may warrant an ACE inhibitor.
Candidates
for a diagnostic cardiac stress test include those with 1)
typical or atypical cardiac symptoms and 2) an abnormal resting
ECG. The screening of asymptomatic patients remains controversial.
Studies
have demonstrated that a significant percentage of patients
with diabetes who have no symptoms of CAD have abnormal stress
tests, either by ECG or echo and nuclear perfusion imaging.
Some of these patients, though clearly not all, have significant
coronary stenoses if they proceed to angiography. It has also
been demonstrated that patients with silent myocardial ischemia
have a poorer prognosis than those with normal stress tests.
Their risk is further accentuated if cardiac autonomic neuropathy
coexists. Candidates for a screening cardiac stress test include
those with 1) a history of peripheral or carotid occlusive
disease and 2) sedentary lifestyle, age >35 years, and
plans to begin a vigorous exercise program. There are no data
to suggest that patients who start to increase their physical
activity by walking or similar exercise increase their risk
of a CVD event and therefore are unlikely to need a stress
test.
It
has previously been proposed to screen those with two or more
additional cardiac risk factors. However, this likely includes
the vast majority of patients with type 2 diabetes (given
that the risk factors frequently cluster). The Detection of
Silent Myocardial Ischemia in Asymptomatic Diabetic Subjects
(DIAD) study suggested that conventional cardiac risk factors
did not help to identify those patients with abnormal perfusion
imaging.
Current evidence suggests that noninvasive tests can improve
assessment of future CHD risk. There is, however, no current
evidence that such testing in asymptomatic patients with risk
factors improves outcomes or leads to better utilization of
treatments.
Approximately
1 in 5 will have an abnormal test, and 1 in 15 will have a
major abnormality. More information is needed concerning prognosis,
and the value of early intervention (invasive or noninvasive)
before widespread screening is recommended. All patients irrespective
of their CAD status should have aggressive risk factor modification,
including control of glucose, lipids, and blood pressure and
prophylactic aspirin therapy.
Patients
with abnormal exercise ECG and patients unable to perform
an exercise ECG require additional or alternative testing.
Currently, stress nuclear perfusion and stress echocardiography
are valuable next-level diagnostic procedures. A consultation
with a cardiologist is recommended regarding further work-up.
When
identified, the optimal therapeutic approach to the diabetic
patient with silent myocardial ischemia is unknown. Certainly
if major CAD is identified, aggressive intervention appears
warranted. If minor stenoses are detected, however, whether
there is any benefit to further invasive evaluation and/or
therapy is unknown. There are no well-conducted prospective
trials with adequate control groups to shed light on this
question. Accordingly, there are no evidence-based guidelines
for screening the asymptomatic diabetic patient for CAD.
B.
Nephropathy screening and treatment
Recommendations
General
recommendations
- To
reduce the risk and/or slow the progression of nephropathy,
optimize glucose control. (A)
- To
reduce the risk and/or slow the progression of nephropathy,
optimize blood pressure control. (A)
- To
reduce the risk of nephropathy, protein intake should be
limited to the RDA (0.8 g/kg) in those with any degree of
CKD. (B)
Screening
- Perform
an annual test for the presence of microalbuminuria in type
1 diabetic patients with diabetes duration of 5 years and
in all type 2 diabetic patients, starting at diagnosis and
during pregnancy. (E)
- Serum
creatinine should be measured at least annually for the
estimation of glomerular filtration rate (GFR) in all adults
with diabetes regardless of the degree of urine albumin
excretion. The serum creatinine alone should not be used
as a measure of kidney function but instead used to estimate
GFR and stage the level of chronic kidney disease (CKD).
(E)
Treatment
- In
the treatment of both micro- and macroalbuminuria, either
ACE inhibitors or ARBs should be used except during pregnancy.
(A)
- While
there are no adequate head-to-head comparisons of ACE inhibitos
and ARBs, there is clinical trial support for each of the
following statements:
In patients with type 1 diabetes, with hypertension and
any degree of albuminuria, ACE inhibitors have been shown
to delay the
progression of nephropathy.
(A)
In patients with type 2 diabetes,
hypertension, and microalbuminuria, ACE inhibitors and ARBs
have been shown to delay the progression to
macroalbuminuria. (A)
In patients with type 2 diabetes,
hypertension, macroalbuminuria, and renal insufficiency
(serum creatinine >1.5 mg/dl), ARBs have been shown
to delay the progression of nephropathy. (A)
If one class is not tolerated,
the other should be substituted. (E)
- With
presence of nephropathy, initiate protein restriction to
0.8 g · kg body wt1 · day1 ( 10%
of daily calories), the current adult RDA for protein. Further
restriction may be useful in slowing the decline of GFR
in patients whose nephropathy is progressing despite maximized
glycemic and blood pressure control and use of ACE inhibitors
and/or ARBs. (B)
- With
regards to slowing the progression of nephropathy, the use
of DCCBs as initial therapy is not more effective than placebo.
Their use in nephropathy should be restricted to additional
therapy to further lower blood pressure in patients already
treated with ACE inhibitors or ARBs. (B)
- In
the setting of albuminuria or nephropathy, in patients unable
to tolerate ACE inhibitors and/or ARBs, consider the use
of non-DCCBs, ß-blockers, or diuretics for the management
of blood pressure. Use of non-DCCBs may reduce albuminuria
in diabetic patients, including during pregnancy. (E)
- If
ACE inhibitors, ARBs, or diuretics are used, monitor serum
potassium levels for the development of hyperkalemia. (B)
- Continued
surveillance of microalbuminuria/proteinuria to assess both
response to therapy and progression of disease is recommended.
(E)
- Consider
referral to a physician experienced in the care of diabetic
renal disease when the estimated (GFR) has fallen to <60
ml/min per 1.73 m2 or if difficulties occur in the management
of hypertension or hyperkalemia. (B)
Diabetic
nephropathy occurs in 2040% of patients with diabetes
and is the single leading cause of end-stage renal disease
(ESRD). Persistent albuminuria in the range of 30299
mg/24 h (microalbuminuria) has been shown to be the earliest
stage of diabetic nephropathy in type 1 diabetes and a marker
for development of nephropathy in type 2 diabetes. Microalbuminuria
is also a well-established marker of increased CVD risk.
Patients
with microalbuminuria who progress to macroalbuminuria ( 300
mg/24 h) are likely to progress to ESRD over a period of years.
Over the past several years, a number of interventions have
been demonstrated to reduce the risk and slow the progression
of renal disease.
Intensive
diabetes management with the goal of achieving near normoglycemia
has been shown in large prospective randomized studies to
delay the onset of microalbuminuria and the progression of
micro- to macroalbuminuria in patients with type 1 and type
2 diabetes. The UKPDS provided strong evidence that control
of blood pressure can reduce the development of nephropathy.
In addition, large prospective randomized studies in patients
with type 1 diabetes have demonstrated that achievement of
lower levels of systolic blood pressure (<140 mmHg) achieved
with treatment using ACE inhibitors provides a selective benefit
over other antihypertensive drug classes in delaying the progression
from micro- to macroalbuminuria and can slow the decline in
GFR in patients with macroalbuminuria.
In
addition, ACE inhibitors have been shown to reduce severe
CVD (i.e., myocardial infarction, stroke, death), thus further
supporting the use of these agents in patients with microalbuminuria.
ARBs have also been shown to reduce the rate of progression
from micro- to macroalbuminuria as well as ESRD in patients
with type 2 diabetes. Some evidence suggests that ARBs have
a smaller magnitude of rise in potassium compared with ACE
inhibitors in people with nephropathy. With regards to slowing
the progression of nephropathy, the use of DCCBs as initial
therapy is not more effective than placebo. Their use in nephropathy
should be restricted to additional therapy to further lower
blood pressure in patients already treated with ACE inhibitors
or ARBs. In the setting of albuminuria or nephropathy, in
patients unable to tolerate ACE inhibitors and/or ARBs, consider
the use of non-DCCBs, ß-blockers, or diuretics for the
management of blood pressure.
Studies
in patients with varying stages of nephropathy have shown
that protein restriction is of benefit in slowing the progression
of albuminuria, GFR decline, and occurrence of ESRD. Protein
restriction should be considered particularly in patients
whose nephropathy seems to be progressing despite optimal
glucose and blood pressure control and use of ACE inhibitor
and/or ARBs.
Screening
for microalbuminuria can be performed by three methods: 1)
measurement of the albumin-to-creatinine ratio in a random
spot collection (preferred method); 2) 24-h collection with
creatinine, allowing the simultaneous measurement of creatinine
clearance; and 3) timed (e.g., 4-h or overnight) collection.
The
analysis of a spot sample for the albumin-to-creatinine ratio
is strongly recommended by most authorities. The other two
alternatives (24-h collection and a timed specimen) are rarely
necessary. Measurement of a spot urine for albumin only, whether
by immunoassay or by using a dipstick test specific for microalbumin,
without simultaneously measuring urine creatinine, is less
expensive than the recommended methods but is susceptible
to false-negative and -positive determinations as a result
of variation in urine concentration due to hydration and other
factors.
At
least two of three tests measured within a 6-month period
should show elevated levels before a patient is designated
as having microalbuminuria. Abnormalities of albumin excretion
are defined in Table
8.
Table
8 Definitions of abnormalities in albumin excretion
|
Category
|
Spot
collection (µg/mg creatinine)
|
|
Normal
|
<30
|
|
Microalbuminuria
|
30299
|
|
Macro
(clinical)-albuminuria
|
>=300
|
Because
of variability in urinary albumin excretion, two of three
specimens collected within a 3- to 6-month period should be
abnormal before considering a patient to have crossed one
of these diagnostic thresholds. Exercise within 24 h, infection,
fever, CHF, marked hyperglycemia, and marked hypertension
may elevate urinary albumin excretion over baseline values.
Screening
for microalbuminuria is indicated in pregnancies complicated
by diabetes, since microalbuminuria in the absence of urinary
tract infection is a strong predictor of superimposed preeclampsia.
In the presence of macroalbuminuria or urine dipstick proteinuria,
estimation of GFR by serum creatinine (see below) or 24-h
urine creatinine clearance is indicated to stage the patients
renal disease, and other tests may be necessary to diagnose
preeclampsia.
Information
on presence of urine albumin excretion in addition to level
of GFR may be used to stage CKD according to the National
Kidney Foundation. The current National Kidney Foundation
classification (Table
9) is primarily based on GFR levels and therefore differs
from some earlier staging systems used by others, in which
staging is based primarily on urinary albumin excretion. Studies
have found decreased GFR in the absence of increase urine
albumin excretion in a substantial percentage of adults with
diabetes. Thus, these studies demonstrate that significant
decline in GFR may be noted in adults with type 1 and type
2 diabetes in the absence of increased urine albumin excretion.
It is now clear that stage 3 or high CKD (GFR <60 ml/min
per 1.73 m2) occurs in the absence of urine albumin excretion
in a substantial proportion of adults with diabetes. Screening
this population for increased urine albumin excretion alone,
therefore, will miss a considerable number of CKD cases.
Table
9 Stages of CKD
|
Stage
|
GFR
(ml/min per 1.73 m2body surface area)
|
Description
|
|
1
|
Kidney damage* with normal or increased GFR
|
90
|
|
2
|
Kidney damage* with mildly decreased GFR
|
6089
|
|
3
|
Moderately decreased GFR
|
3059
|
|
4
|
Severely decreased GFR
|
1529
|
|
5
|
Kidney failure
|
<15
or dialysis
|
|
*
Kidney damage defined as abnormalities on pathologic, urine,
blood, or imaging tests. Adapted from ref. 167.
Serum creatinine should be measured at least annually for
the estimation of GFR in all adults with diabetes regardless
of the degree of urine albumin excretion. Serum creatinine
alone should not be used as a measure of kidney function,
but used to estimate GFR and stage the level of CKD. The GFR
can be easily estimated using formulae like the Cockroft-Gault
formula or a newer prediction formula developed by researchers
using data collected from the Modification of Diet and Renal
Disease (MDRD) study. The estimated GFR can easily be calculated
by going to http://www.kidney.org/professionals/kdoqi/gfr_calculator.cfm.
The
role of annual microalbumuria assessment is less clear after
diagnosis of microalbuminuria and institution of ACE inhibitor
or ARB therapy and blood pressure control. Most experts, however,
recommend continued surveillance to assess both response to
therapy and progression of disease. Some experts suggest that
reducing urine microalbuminuria to the normal or near-normal
range, if possible, may improve renal and cardiovascular prognosis.
This approach has not been formally evaluated in prospective
trials.
Consider
referral to a physician experienced in the care of diabetic
renal disease either when the GFR has fallen to <60 ml/min
per 1.73 m2 or if difficulties occur in the management of
hypertension or hyperkalemia. It is suggested that consultation
with a nephrologist be obtained when the GFR is <30 ml/min
per 1.73 m2. Early referral of such patients has been found
to reduce cost and improve quality of care and keep people
off dialysis longer.
Because
of variability in urinary albumin excretion, two of three
specimens collected within a 3- to 6-month period should be
abnormal before considering a patient to have crossed one
of these diagnostic thresholds. Exercise within 24 h, infection,
fever, CHF, marked hyperglycemia, and marked hypertension
may elevate urinary albumin excretion over baseline values.
C.
Retinopathy screening and treatment
Recommendations
General
recommendations
- Optimal
glycemic control can substantially reduce the risk and progression
of diabetic retinopathy. (A)
- Optimal
blood pressure control can reduce the risk and progression
of diabetic retinopathy. (A)
- Aspirin
therapy does not prevent retinopathy or increase the risks
of hemorrhage. (A)
Screening
- Adults
and adolescents with type 1 diabetes should have an initial
dilated and comprehensive eye examination by an ophthalmologist
or optometrist within 35 years after the onset of
diabetes. (B)
- Patients
with type 2 diabetes should have an initial dilated and
comprehensive eye examination by an ophthalmologist or optometrist
shortly after the diagnosis of diabetes. (B)
- Subsequent
examinations for type 1 and type 2 diabetic patients should
be repeated annually by an ophthalmologist or optometrist.
Less frequent exams (every 23 years) may be considered
in the setting of a normal eye exam. Examinations will be
required more frequently if retinopathy is progressing.
(B)
- Women
who are planning pregnancy or who have become pregnant should
have a comprehensive eye examination and should be counseled
on the risk of development and/or progression of diabetic
retinopathy. Eye examination should occur in the first trimester
with close follow-up throughout pregnancy and for 1 year
postpartum. This guideline does not apply to women who develop
GDM because such individuals are not at increased risk for
diabetic retinopathy. (B)
Treatment
- Laser
therapy can reduce the risk of vision loss in patients with
high-risk characteristics (HRCs). (A)
- Promptly
refer patients with any level of macular edema, severe NPDR,
or any PDR to an ophthalmologist who is knowledgeable and
experienced in the management and treatment of diabetic
retinopathy. (A)
Diabetic
retinopathy is a highly specific vascular complication of
both type 1 and type 2 diabetes. The prevalence of retinopathy
is strongly related to the duration of diabetes. Diabetic
retinopathy is estimated to be the most frequent cause of
new cases of blindness among adults aged 2074 years.
Glaucoma, cataracts, and other disorders of the eye may occur
earlier in people with diabetes and should also be evaluated.
Intensive
diabetes management with the goal of achieving near normoglycemia
has been shown in large prospective randomized studies to
prevent and/or delay the onset of diabetic retinopathy. In
addition to glycemic control, several other factors seem to
increase the risk of retinopathy. The presence of nephropathy
is associated with retinopathy. High blood pressure is an
established risk factor for the development of macular edema
and is associated with the presence of PDR. Lowering blood
pressure, as demonstrated by the UKPDS, has been shown to
decrease the progression of retinopathy. Several case series
and a controlled prospective study suggest that pregnancy
in type 1 diabetic patients may aggravate retinopathy. During
pregnancy and 1 year postpartum, retinopathy may be transiently
aggravated; laser photocoagulation surgery can minimize this
risk.
Patients
with type 1 diabetes should have an initial dilated and comprehensive
eye examination by an ophthalmologist or optometrist within
5 years after the onset of diabetes. Patients with type 2
diabetes should have an initial dilated and comprehensive
eye examination by an ophthalmologist or optometrist shortly
after the diagnosis of diabetes. Subsequent examinations for
type 1 and type 2 diabetic patients should be repeated annually
by an ophthalmologist or optometrist who is knowledgeable
and experienced in diagnosing the presence of diabetic retinopathy
and is aware of its management. Less frequent exams (every
23 years) may be considered with the advice of an eye
care professional in the setting of a normal eye exam. Examinations
will be required more frequently if retinopathy is progressing.
Examinations
can also be done by the taking of retinal photographs (with
or without dilation of the pupil) and having these read by
experienced experts in this field. In-person exams are still
necessary when the photos are unacceptable and for follow
up of abnormalities detected. This technology has it greatest
potential in areas where qualified eye care professionals
are not available. Results of eye examinations should be documented
and transmitted to the referring health care professional.
One
of the main motivations for screening for diabetic retinopathy
is the established efficacy of laser photocoagulation surgery
in preventing visual loss. Two large National Institutes of
Healthsponsored trials, the Diabetic Retinopathy Study
(DRS) and the Early Treatment Diabetic Retinopathy Study (ETDRS),
provide the strongest support for the therapeutic benefit
of photocoagulation surgery.
The
DRS tested whether scatter (panretinal) photocoagulation surgery
could reduce the risk of vision loss from PDR. Severe visual
loss (i.e., best acuity of 5/200 or worse) was seen in 15.9%
of untreated vs. 6.4% of treated eyes. The benefit was greatest
among patients whose baseline evaluation revealed HRCs (chiefly
disc neovascularization or vitreous hemorrhage with any retinal
neovascularization). Of control eyes with HRCs, 26% progressed
to severe visual loss vs. 11% of treated eyes. Given the risk
of a modest loss of visual acuity and of contraction of visual
field from panretinal laser surgery, such therapy has been
primarily recommended for eyes approaching or reaching HRCs.
The
ETDRS established the benefit of focal laser photocoagulation
surgery in eyes with macular edema, particularly those with
clinically significant macular edema. In patients with clinically
significant macular edema after 2 years, 20% of untreated
eyes had a doubling of the visual angle (e.g., 20/50 to 20/100)
compared with 8% of treated eyes. Other results from the ETDRS
indicate that, provided careful follow-up can be maintained,
scatter photocoagulation surgery is not recommended for eyes
with mild or moderate NPDR. When retinopathy is more severe,
scatter photocoagulation surgery should be considered, and
usually should not be delayed, if the eye has reached the
high-risk proliferative stage. In older-onset patients with
severe NPDR or less-than-high-risk PDR, the risk of severe
visual loss and vitrectomy is reduced 50% by laser photocoagulation
surgery at these earlier stages.
Laser
photocoagulation surgery in both the DRS and the ETDRS was
beneficial in reducing the risk of further visual loss, but
generally not beneficial in reversing already diminished acuity.
This preventive effect and the fact that patients with PDR
or macular edema may be asymptomatic provide strong support
for a screening program to detect diabetic retinopathy. For
a detailed review of the evidence and further discussion,
see the ADAs technical review and position statement
on this subject.
D.
Neuropathy screening and treatment
Recommendations
- All
patients should be screened for distal symmetric polyneuropathy
(DPN) at diagnosis and at least annually thereafter, using
simple clinical tests. (A)
- Electrophysiological
testing is rarely ever needed, except in situations where
the clinical features are atypical. (E)
- Once
the diagnosis of DPN is established, special foot care is
appropriate for insensate feet to decrease the risk of amputation.
(B)
- Simple
inspection of insensate feet should be performed at 3- to
6-month intervals. An abnormality should trigger referral
for special footwear, preventive specialist, or podiatric
care. (B)
- Screening
for autonomic neuropathy should be instituted at diagnosis
of type 2 diabetes and 5 years after the diagnosis of type
1 diabetes. Special electrophysiological testing for autonomic
neuropathy is rarely needed and may not affect management
and outcomes. (E)
- Education
of patients about self-care of the feet and referral for
special shoes/inserts are vital components of patient management.
(B)
- A
wide variety of medications is recommended for the relief
of specific symptoms related to autonomic neuropathy and
are recommended, as they improve the quality of life of
the patient. (E)
The
diabetic neuropathies are heterogeneous with diverse clinical
manifestations. They may be focal or diffuse. Most common
among the neuropathies are chronic sensorimotor DPN and autonomic
neuropathy. Although DPN is a diagnosis of exclusion, complex
investigations to exclude other conditions are rarely needed.
The
early recognition and appropriate management of neuropathy
in the patient with diabetes is important for a number of
reasons:
1) nondiabetic neuropathies may be present in patients with
diabetes and may be treatable;
2) a number of treatment options exist for symptomatic diabetic
neuropathy;
3) up to 50% of DPN may be asymptomatic and patients are at
risk of insensate injury to their feet;
4) autonomic neuropathy may involve every system in the body;
and
5) cardiovascular autonomic neuropathy causes substantial
morbidity and mortality. Specific treatment for the underlying
nerve damage is currently not available, other than improved
glycemic control, which may slow progression but rarely reverses
neuronal loss. Effective symptomatic treatments are available
for the manifestations of DPN and autonomic neuropathy.
Diagnosis
of neuropathy
Patients
with diabetes should be screened annually for DPN using tests
such as pinprick sensation, temperature and vibration perception
(using a 128-Hz tuning fork), 10-g monofilament pressure sensation
at the dorsal surface of both great toes, just proximal to
the nail bed, and ankle reflexes. Combinations of more than
one test have >87% sensitivity in detecting DPN. Loss of
10-g monofilament perception and reduced vibration perception
predict foot ulcers. A minimum of one clinical test should
be carried out annually, and the use of two tests will increase
diagnostic ability.
Focal
and multifocal neuropathy assessment requires clinical examination
in the area related to the neurological symptoms.
Diabetic
autonomic neuropathy
The
symptoms of autonomic dysfunction should be elicited carefully
during the history and review of systems, particularly since
many of these symptoms are potentially treatable. Major clinical
manifestations of diabetic autonomic neuropathy include resting
tachycardia, exercise intolerance, orthostatic hypotension,
constipation, gastroparesis, erectile dysfunction, sudomotor
dysfunction, impaired neurovascular function, "brittle
diabetes," and hypoglycemic autonomic failure.
Cardiovascular
autonomic neuropathy is the most studied and clinically important
form of diabetic autonomic neuropathy. Cardiac autonomic neuropathy
may be indicated by resting tachycardia (>100 bpm), orthostasis
(a fall in systolic blood pressure >20 mmHg upon standing),
or other disturbances in autonomic nervous system function
involving the skin, pupils, or gastrointestinal and genitourinary
systems.
Gastrointestinal
disturbances (e.g., esophageal enteropathy, gastroparesis,
constipation, diarrhea, fecal incontinence) are common, and
any section of the gastrointestinal tract may be affected.
Gastroparesis should be suspected in individuals with erratic
glucose control. Upper gastrointestinal symptoms should lead
to consideration of all possible causes, including autonomic
dysfunction. Evaluation of solid-phase gastric emptying using
double-isotope scintigraphy may be done if symptoms are suggestive,
but test results often correlate poorly with symptoms. Barium
studies or referral for endoscopy may be required to rule
out structural abnormalities. Constipation is the most common
lower gastrointestinal symptom but can alternate with episodes
of diarrhea. Endoscopy may be required to rule out other causes.
Diabetic
autonomic neuropathy is also associated with genitourinary
tract disturbances, including bladder and/or sexual dysfunction.
Evaluation of bladder dysfunction should be performed for
individuals with diabetes who have recurrent urinary tract
infections, pyelonephritis, incontinence, or a palpable bladder.
In men, diabetic autonomic neuropathy may cause loss of penile
erection and/or retrograde ejaculation.
Symptomatic
treatments
DPN.
The
first step in management of patients with DPN should be to
aim for stable and optimal glycemic control. Although controlled
trial evidence is lacking, several observational studies suggest
that neuropathic symptoms improve not only with optimization
of control but also with the avoidance of extreme blood glucose
fluctuations. Most patients will require pharmacological treatment
for painful symptoms: many agents have efficacy confirmed
in published randomized controlled trials, though none are
specifically licensed for the management of painful DPN.
Tricyclic
drugs.
The
usefulness of the tricyclic drugs such as amitriptyline and
imipramine has been confirmed in several randomized controlled
trials, although they do not have formal FDA approval for
this condition. Although cheap and generally efficacious in
the management of neuropathic pain, side effects limit their
use in many patients. Tricylcic drugs may also exacerbate
some autonomic symptoms such as gastroparesis.
Anticonvulsants.
Gabapentin
is a commonly prescribed anticonvulsant that has been shown
to be efficacious in the treatment of neuropathic pain, although
not approved for this condition. It is advisable to start
at a small dose and then increase over days to weeks to the
dosage that is well tolerated and produces symptomatic relief.
The structurally related compound pregabalin is longer acting,
has recently been confirmed to be useful in painful diabetic
neuropathy in a randomized controlled trial, and is approved
for use in this condition. Other anticonvulsant drugs may
also be efficacious in the management of neuropathic pain.
Other
agents.
The
5-hydroxytryptamine and norepinephrine reuptake inhibitor
duloxetine has been approved by the FDA for the treatment
of neuropathic pain.
Treatment of autonomic neuropathy
A
wide variety of agents are used to treat the symptoms of autonomic
neuropathy including metoclopramide for gastroparesis and
several medications for bladder and erectile dysfunction.
These treatments are frequently used to provide symptomatic
relief to patients. Although they do not change the underlying
pathology and natural history of the disease process, their
use is recommended due to the impact they may have on the
quality of life of the patient.
E.
Foot care
Recommendations
- Perform
a comprehensive foot examination and provide foot self care
education annually on patients with diabetes to identify
risk factors predictive of ulcers and amputations. (B)
- The
foot examination can be accomplished in a primary care setting
and should include the use of a monofilament, tuning fork,
palpation, and a visual examination. (B)
- A
multidisciplinary approach is recommended for individuals
with foot ulcers and high-risk feet, especially those with
a history of prior ulcer or amputation. (B)
- Refer
patients who smoke or with prior lower-extremity complications
to foot care specialists for ongoing preventive care and
life-long surveillance. (C)
- Initial
screening for peripheral arterial disease (PAD) should include
a history for claudication and an assessment of the pedal
pulses. Consider obtaining an ankle-brachial index (ABI),
as many patients with PAD are asymptomatic. (C)
- Refer
patients with significant claudication or a positive ABI
for further vascular assessment and consider exercise, medications,
and surgical options. (C)
Amputation
and foot ulceration are the most common consequences of diabetic
neuropathy and major causes of morbidity and disability in
people with diabetes. Early recognition and management of
independent risk factors can prevent or delay adverse outcomes.
The
risk of ulcers or amputations is increased in people who have
had diabetes >10 years, are male, have poor glucose control,
or have cardiovascular, retinal, or renal complications. The
following foot-related risk conditions are associated with
an increased risk of amputation:
- Peripheral
neuropathy with loss of protective sensation.
- Altered
biomechanics (in the presence of neuropathy).
- Evidence
of increased pressure (erythema, hemorrhage under a callus).
- Bony
deformity.
-
Peripheral vascular disease (decreased or absent pedal pulses).
- A
history of ulcers or amputation.
- Severe
nail pathology.
All
individuals with diabetes should receive an annual foot examination
to identify high-risk foot conditions. This examination should
include assessment of protective sensation, foot structure
and biomechanics, vascular status, and skin integrity. People
with one or more high-risk foot condition should be evaluated
more frequently for the development of additional risk factors.
People with neuropathy should have a visual inspection of
their feet at every visit with a health care professional.
Evaluation of neurological status in the low-risk foot should
include a quantitative somatosensory threshold test, using
the Semmes-Weinstein 5.07 (10-g) monofilament. The skin should
be assessed for integrity, especially between the toes and
under the metatarsal heads. The presence of erythema, warmth,
or callus formation may indicate areas of tissue damage with
impending breakdown. Bony deformities, limitation in joint
mobility, and problems with gait and balance should be assessed.
People
with neuropathy or evidence of increased plantar pressure
may be adequately managed with well-fitted walking shoes or
athletic shoes. Patients should be educated on the implications
of sensory loss and the ways to substitute other sensory modalities
(hand palpation, visual inspection) for surveillance of early
problems. People with evidence of increased plantar pressure
(e.g., erythema, warmth, callus, or measured pressure) should
use footwear that cushions and redistributes the pressure.
Callus can be debrided with a scalpel by a foot care specialist
or other health professional with experience and training
in foot care. People with bony deformities (e.g., hammertoes,
prominent metatarsal heads, or bunions) may need extra-wide
shoes or depth shoes. People with extreme bony deformities
(e.g., Charcot foot) that cannot be accommodated with commercial
therapeutic footwear may need custom-molded shoes.
Initial
screening for PAD should include a history for claudication
and an assessment of the pedal pulses. Consider obtaining
an ABI, as many patients with PAD are asymptomatic. Refer
patients with significant or a positive ABI for further vascular
assessment and consider exercise, medications, and surgical
options.
Patients
with diabetes and high-risk foot conditions should be educated
regarding their risk factors and appropriate management. Patients
at risk should understand the implications of the loss of
protective sensation, the importance of foot monitoring on
a daily basis, the proper care of the foot, including nail
and skin care, and the selection of appropriate footwear.
The patients understanding of these issues and their
physical ability to conduct proper foot surveillance and care
should be assessed. Patients with visual difficulties, physical
constraints preventing movement, or cognitive problems that
impair their ability to assess the condition of the foot and
to institute appropriate responses will need other people,
such as family members, to assist in their care. Patients
at low risk may benefit from education on foot care and footwear.
For
a detailed review of the evidence and further discussion,
see the ADAs technical review and position statement
in this subject.
Problems involving the feet, especially ulcers and wound care,
may require care by a podiatrist, orthopedic surgeon, or rehabilitation
specialist experienced in the management of individuals with
diabetes. For a complete discussion on wound care, see the
ADAs consensus statement on diabetic foot wound care.
|
VII.
DIABETES CARE IN SPECIFIC POPULATIONS
|
A.
Children and adolescents
1.
Type 1 diabetes
Although
approximately three-quarters of all cases of type 1 diabetes
are diagnosed in individuals <18 years of age, historically,
ADA recommendations for management of type 1 diabetes have
pertained most directly to adults with type 1 diabetes. Because
children are not simply "small adults," it is appropriate
to consider the unique aspects of care and management of children
and adolescents with type 1 diabetes. Children with diabetes
differ from adults in many respects, including insulin sensitivity
related to sexual maturity, physical growth, ability to provide
self-care, and unique neurologic vulnerability to hypoglycemia.
Attention to such issues as family dynamics, developmental
stages, and physiologic differences related to sexual maturity
all are essential in developing and implementing an optimal
diabetes regimen. Although current recommendations for children
and adolescents are less likely to be based on evidence derived
from rigorous research because of current and historical restraints
placed on conducting research in children, expert opinion
and a review of available and relevant experimental data are
summarized in a recent ADA Statement. The following represents
a summary of recommendations and guidelines pertaining specifically
to the care and management of children and adolescents that
are included in that document.
Ideally,
the care of a child or adolescent with type 1 diabetes should
be provided by a multidisciplinary team of specialists trained
in the care of children with pediatric diabetes, although
this may not always be possible. At the very least, education
of the child and family should be provided by health care
providers trained and experienced in childhood diabetes and
sensitive to the challenges posed by diabetes in this age-group.
At the time of initial diagnosis, it is essential that diabetes
education be provided in a timely fashion, with the expectation
that the balance between adult supervision and self-care should
be defined by, and will evolve according to, physical, psychologic,
and emotional maturity. MNT should be provided at diagnosis,
and at least annually thereafter, by an individual experienced
with the nutritional needs of the growing child and the behavioral
issues that have an impact on adolescent diets.
a.
Glycemic control
While
current standards for diabetes management reflect the need
to maintain glucose control as near to normal as safely possible,
special consideration must be given to the unique risks of
hypoglycemia in young children. Glycemic goals need to be
modified to take into account the fact that most children
<6 or 7 years of age have a form of "hypoglycemic
unawareness," in that counterregulatory mechanisms are
immature, and young children lack the cognitive capacity to
recognize and respond to hypoglycemic symptoms, placing them
at greater risk for hypoglycemia and its sequelae. In addition,
extensive evidence indicates that near normalization of blood
glucose levels is seldom attainable in children and adolescents
after the honeymoon (remission) period. The A1C level achieved
in the "intensive" adolescent cohort of the DCCT
group was >1% higher than that achieved for older patients
and current ADA recommendations for patients in general.
In
selecting glycemic goals, the benefits of achieving a lower
A1C must be weighed against the unique risks of hypoglycemia
and the disadvantages of targeting a higher, although more
achievable, goal that may not promote optimal long-term health
outcomes. Age-specific glycemic and A1C goals are presented
in Table 10.
Table
10 Plasma blood glucose and A1C goals for type 1 diabetes
by age group
Values
by age (years) Plasma blood glucose goal range (mg/dl) A1C
Rationale
Before meals Bedtime/overnight
Toddlers and preschoolers (06) 100180 110200
<8.5% (but >7.5%) High risk and vulnerability to hypoglycemia
School age (612) 90180 100180 <8% Risks
of hypoglycemia and relatively low risk of complications prior
to puberty
Adolescents and young adults (1319) 90130 90150
<8% Risk of severe hypoglycemia
Developmental and psychological issues
A lower goal (<7.0%) is reasonable if it can be
achieved without excessive hypoglycemia
Key concepts in setting glycemic goals:
Goals should be individualized and lower goals may
be reasonable based on benefit-risk assessment.
Blood glucose goals should be higher than those listed
above in children with frequent hypoglycemia or hypoglycemia
unawareness.
Postprandial blood glucose values should be measured
when there is a disparity between preprandial blood glucose
values and A1C levels.
b.
Screening and management of chronic complications in children
and adolescents with type 1 diabetes.
i.
Nephropathy
Recommendations
- Annual
screening for microalbuminuria should be initiated once
the child is 10 years of age and has had diabetes for 5
years. Screening may be done with a random spot urine sample
analyzed for microalbumin-to-creatinine ratio. (E)
- Confirmed,
persistently elevated microalbumin levels should be treated
with an ACE inhibitor, titrated to normalization of microalbumin
excretion (if possible). (E)
ii.
Hypertension
Recommendations
- Treatment
of high-normal blood pressure (systolic or diastolic blood
pressure consistently above the 90th percentile for age,
sex, and height) should include dietary intervention and
exercise, aimed at weight control and increased physical
activity, if appropriate. If target blood pressure is not
reached within 36 months of lifestyle intervention,
pharmacologic treatment should be initiated. (E)
- Pharmacologic
treatment of hypertension (systolic or diastolic blood pressure
consistently above the 95th percentile for age, sex, and
height or consistently greater than 130/80 mmHg, if 95%
exceeds that value) should be initiated as soon as the diagnosis
is confirmed. (E)
- ACE
inhibitors should be considered for the initial treatment
of hypertension. (E)
- Hypertension
in childhood is defined as an average systolic or diastolic
blood pressure 95th percentile for age, sex, and height
percentile measured on at least three separate days. "High-normal"
blood pressure is defined as an average systolic or diastolic
blood pressure 90th but <95th percentile for age, sex,
and height percentile measured on at least 3 separate days.
Normal blood pressure levels for age, sex, and height and
appropriate methods for determinations are available online
at www.nhlbi.nih.gov/health/prof/heart/hbp/hbp_ped.pdf.
iii.
Dyslipidemia
Recommendations
Screening
- Prepubertal
children: a fasting lipid profile should be performed on
all children >2 years of age at the time of diagnosis
(after glucose control has been established) if there is
a family history of hypercholesterolemia (total cholesterol
>240 mg/dl), if there is a history of a cardiovascular
event before age 55 years, or if family history is unknown.
If family history is not of concern, then the first lipid
screening should be performed at puberty (>12 years).
If values are within the accepted risk levels (LDL <100
mg/dl [2.6 mmol/l]), a lipid profile should be repeated
every 5 years. (E)
- Pubertal
children (>12 years of age): a fasting lipid profile
should be performed at the time of diagnosis (after glucose
control has been established). If values fall within the
accepted risk levels (LDL <100 mg/dl [2.6 mmol/l]), the
measurement should be repeated every 5 years. (E)
- If
lipids are abnormal, annual monitoring is recommended in
both age-groups. (E)
Treatment
- Treatment
should be based on fasting lipid levels (mainly LDL) obtained
after glucose control is established. (E)
- Initial
therapy should consist of optimization of glucose control
and MNT aimed at a decrease in the amount of saturated fat
in the diet. (E)
- The
addition of a pharmacologic lipid-lowering agents is recommended
for LDL >160 mg/dl (4.1 mmol/l), and is also recommended
in patients who have LDL cholesterol values of 130159
mg/dl (3.44.1 mmol/l) based on the patients
CVD risk profile, after failure of MNT and lifestyle changes.
(E)
- The
goal of therapy is an LDL value <100 mg/dl (2.6 mmol/l).
(E)
iv.
Retinopathy
Recommendations
- The
first ophthalmologic examination should be obtained once
the child is 10 years of age and has had diabetes for 35
years. (E)
- After
the initial examination, annual routine follow-up is generally
recommended. Less frequent examinations may be acceptable
on the advice of an eye care professional. (E)
Although
retinopathy most commonly occurs after the onset of puberty
and after 510 years of diabetes duration, it has been
reported in prepubertal children and with diabetes duration
of only 12 years. Referrals should be made to eye care
professionals with expertise in diabetic retinopathy, an understanding
of the risk for retinopathy in the pediatric population, and
experience in counseling the pediatric patient and family
on the importance of early prevention/intervention.
c.
Other issues.
A
major issue deserving emphasis in this age-group is that of
"adherence." No matter how sound the medical regimen,
it can only be as good as the ability of the family and/or
individual to implement it. Family involvement in diabetes
remains an important component of optimal diabetes management
throughout childhood and into adolescence. Health care providers
who care for children and adolescents, therefore, must be
capable of evaluating the behavioral, emotional, and psychosocial
factors that interfere with implementation and then must work
with the individual and family to resolve problems that occur
and/or to modify goals as appropriate.
Since
a sizable portion of a childs day is spent in school,
close communication with school or day care personnel is essential
for optimal diabetes management. Information should be supplied
to school personnel, so that they may be made aware of the
diagnosis of diabetes in the student and of the signs, symptoms,
and treatment of hypoglycemia. In most cases it is imperative
that blood glucose testing be performed at the school or day
care setting before lunch and when signs or symptoms of abnormal
blood glucose levels are present. Many children may require
support for insulin administration by either injection or
continuous subcutaneous insulin infusion before lunch (and
often also before breakfast) at school or in day care. For
further discussion, see the ADA position statement and the
report from the National Diabetes Education Program.
2.
Type 2 diabetes
Finally,
the incidence of type 2 diabetes in children and adolescents
has been shown to be increasing, especially in ethnic minority
populations. Distinction between type 1 and type 2 diabetes
in children can be difficult, since autoantigens and ketosis
may be present in a substantial number of patients with otherwise
straightforward type 2 diabetes (including obesity and acanthosis
nigricans). Such a distinction at the time of diagnosis is
critical since treatment regimens, educational approaches,
and dietary counsel will differ markedly between the two diagnoses.
The ADA consensus statement provides guidance to the prevention,
screening, and treatment of type 2 diabetes, as well as its
comorbidities in young people.
B.
Preconception care
Recommendations
- A1C
levels should be normal or as close to normal as possible
(<1% above the upper limits of normal) in an individual
patient before conception is attempted. (B)
- All
women with diabetes and child-bearing potential should be
educated about the need for good glucose control before
pregnancy. They should participate in family planning. (E)
- Women
with diabetes who are contemplating pregnancy should be
evaluated and, if indicated, treated for diabetic retinopathy,
nephropathy, neuropathy, and CVD. (E)
- Among
the drugs commonly used in the treatment of patients with
diabetes, statins are pregnancy category X and should be
discontinued before conception if possible. ACE inhibitors
and ARBs are category C in the first trimester (maternal
benefit may outweigh fetal risk in certain situations),
but category D in later pregnancy, and should generally
be discontinued before pregnancy. Among the oral antidiabetic
agents, metformin and acarbose are classified as category
B and all others as category C; potential risks and benefits
of oral antidiabetic agents in the preconception period
must be carefully weighed, recognizing that sufficient data
are not available to establish the safety of these agents
in pregnancy. They should generally be discontinued in pregnancy.
(E)
Major
congenital malformations remain the leading cause of mortality
and serious morbidity in infants of mothers with type 1 and
type 2 diabetes. Observational studies indicate that the risk
of malformations increases continuously with increasing maternal
glycemia during the first 68 weeks of gestation, as
defined by first-trimester A1C concentrations. There is no
threshold for A1C values above which the risk begins or below
which it disappears. However, malformation rates above the
12% background rate seen in nondiabetic pregnancies
appear to be limited to pregnancies in which first-trimester
A1C concentrations are >1% above the normal range.
Preconception
care of diabetes appears to reduce the risk of congenital
malformations. Five nonrandomized studies have compared rates
of major malformations in infants between women who participated
in preconception diabetes care programs and women who initiated
intensive diabetes management after they were already pregnant.
The preconception care programs were multidisciplinary and
designed to train patients in diabetes self-management with
diet, intensified insulin therapy, and SMBG. Goals were set
to achieve normal blood glucose concentrations, and >80%
of subjects achieved normal A1C concentrations before they
became pregnant. In all five studies, the incidence of major
congenital malformations in women who participated in preconception
care (range 1.01.7% of infants) was much lower than
the incidence in women who did not participate (range 1.410.9%
of infants). One limitation of these studies is that participation
in preconception care was self-selected by patients rather
than randomized. Thus, it is impossible to be certain that
the lower malformation rates resulted fully from improved
diabetes care. Nonetheless, the overwhelming evidence supports
the concept that malformations can be reduced or prevented
by careful management of diabetes before pregnancy.
Planned
pregnancies greatly facilitate preconception diabetes care.
Unfortunately, nearly two-thirds of pregnancies in women with
diabetes are unplanned, leading to a persistent excess of
malformations in infants of diabetic mothers. To minimize
the occurrence of these devastating malformations, standard
care for all women with diabetes who have child-bearing potential
should include 1) education about the risk of malformations
associated with unplanned pregnancies and poor metabolic control
and 2) use of effective contraception at all times, unless
the patient is in good metabolic control and actively trying
to conceive.
Women
contemplating pregnancy need to be seen frequently by a multidisciplinary
team experienced in the management of diabetes before and
during pregnancy. Teams may vary but should include a diabetologist,
an internist or a family physician, an obstetrician, a diabetes
educator, a dietitian, a social worker, and other specialists
as necessary. The goals of preconception care are to
1) integrate the patient into the management of her diabetes,
2) achieve the lowest A1C test results possible without excessive
hypoglycemia,
3) assure effective contraception until stable and acceptable
glycemia is achieved, and
4) identify, evaluate, and treat long-term diabetic complications
such as retinopathy, nephropathy, neuropathy, hypertension,
and CAD.
For
further discussion, see the ADAs technical review and
position statement on this subject.
C.
Older individuals
Diabetes
is an important health condition for the aging population;
at least 20% of patients over the age of 65 years have diabetes.
The number of older individuals with diabetes can be expected
to grow rapidly in the coming decades. A recent publication
contains evidence-based guidelines produced in conjunction
with the American Geriatric Society. This document contains
an excellent discussion of this area, and specific guidelines
and language from it have been incorporated below. Unfortunately,
there are no long-term studies in individuals >65 years
of age demonstrating the benefits of tight glycemic control,
blood pressure, and lipid control. Older individuals with
diabetes have higher rates of premature death, functional
disability, and coexisting illnesses such as hypertension,
CHD, and stroke than those without diabetes. Older adults
with diabetes are also at greater risk than other older adults
for several common geriatric syndromes, such as polypharmacy,
depression, cognitive impairment, urinary incontinence, injurious
falls, and persistent pain.
The
care of older adults with diabetes is complicated by their
clinical and functional heterogeneity. Some older individuals
developed diabetes in middle age and face years of comorbidity;
others who are newly diagnosed may have had years of undiagnosed
comorbidity or few complications from the disease. Some older
adults with diabetes are frail and have other underlying chronic
conditions, substantial diabetes-related comorbidity, or limited
physical or cognitive functioning, but other older individuals
with diabetes have little comorbidity and are active. Life
expectancies are also highly variable for this population.
Clinicians caring for older adults with diabetes must take
this heterogeneity into consideration when setting and prioritizing
treatment goals.
All
this having been said, patients who can be expected to live
long enough to reap the benefits of long-term intensive diabetes
management ( 10 years) and who are active, cognitively intact,
and willing to undertake the responsibility of self-management
should be encouraged to do so and be treated using the stated
goals for younger adults with diabetes.
There
is good evidence from middle-aged and older adults suggesting
that multidisciplinary interventions that provide education
on medication use, monitoring, and recognizing hypo- and hyperglycemia
can significantly improve glycemic control. Although control
of hyperglycemia is important, in older individuals with diabetes,
greater reductions in morbidity and mortality may result from
control of all cardiovascular risk factors rather than from
tight glycemic control alone. There is strong evidence from
clinical trials of the value of treating hypertension in the
elderly. There is less evidence for lipid-lowering and aspirin
therapy, although as diabetic patients have such an elevated
risk for CVD, aggressive management of lipids and aspirin
use when not contraindicated are reasonable interventions.
As
noted above, for patients with advanced diabetes complications,
life-limiting comorbid illness, or cognitive or functional
impairment, it is reasonable to set less intensive glycemic
target goals. These patients are less likely to benefit from
reducing the risk of microvascular complications and more
likely to suffer serious adverse effects from hypoglycemia.
Patients with poorly controlled diabetes may be subject to
acute complications of diabetes, including hyperglycemic hyperosmolar
coma. Older patients can be treated with the same drug regimens
as younger patients, but special care is required in prescribing
and monitoring drug therapy. Metformin is often contraindicated
because of renal insufficiency or heart failure. Sulfonylureas
and other insulin secretagogues can cause hypoglycemia. Insulin
can also cause hypoglycemia as well as require good visual
and motor skills and cognitive ability of the patient or a
caregiver. TZDs should not be used in patients with CHF (New
York Heart Association class III and IV). Drugs should be
started at the lowest dose and titrated up gradually until
targets are reached or side effects develop. As well as regards
blood pressure and lipid management, the potential benefits
must always be weighed against potential risks.
|
VIII. DIABETES CARE IN SPECIFIC SETTINGS
|
A.
Diabetes care in the hospital
Recommendations
- All
patients with diabetes admitted to the hospital should be
identified in the medical record as having diabetes. (E)
- All
patients with diabetes should have an order for blood glucose
monitoring, with results available to all members of the
health care team. (E)
- Goals
for blood glucose levels:
|
Critically ill patients: blood glucose levels should
be kept as close to 110 mg/dl (6.1 mmol/l) as possible
and generally <180 mg/dl (10 mmol/l). These patients
will usually require intravenous insulin. (B)
Noncritically ill patients: premeal blood
glucose levels should be kept as close to 90130
mg/dl (5.07.2 mmol/l; midpoint of range 110
mg/dl) as possible given the clinical situation
and postprandial blood glucose levels <180 mg/dl.
Insulin should be used as necessary. (E)
Due to concerns regarding the risk of hypoglycemia,
some institutions may consider these blood glucose
levels to be overly aggressive for initial targets.
Through quality improvement, glycemic goals should
systematically be reduced to the recommended levels.
(E)
|
- Scheduled
prandial insulin doses should be given in relation to meals
and should be adjusted according to point of care glucose
levels. The traditional sliding-scale insulin regimens are
ineffective and are not recommended. (C)
- A
plan for treating hypoglycemia should be established for
each patient. Episodes of hypoglycemia in the hospital should
be tracked. (E)
- All
patients with diabetes admitted to the hospital should have
an A1C obtained for discharge planning if the result of
testing in the previous 23 months is not available.
(E)
- A
diabetes education plan including "survival skills
education" and follow-up should be developed for each
patient. (E)
- Patients
with hyperglycemia in the hospital who do not have a diagnosis
of diabetes should have appropriate plans for follow-up
testing and care documented at discharge. (E)
The
management of diabetes in the hospital is extensively reviewed
in an ADA technical review by Clement et al.. This review
forms the basis for these guidelines. In addition, the American
Association of Clinical Endocrinologists held a conference
on this topic, and the recommendations from this meeting were
also carefully reviewed and discussed in the formulation of
the guidelines that follow. The management of diabetes in
the hospital is generally considered secondary in importance
compared with the condition that prompted admission.
Patients
with hyperglycemia fall into three categories:
- Medical
history of diabetes: diabetes has been previously diagnosed
and acknowledged by the patients treating physician.
- Unrecognized
diabetes: hyperglycemia (fasting blood glucose 126 mg/dl
or random blood glucose 200 mg/dl) occurring during hospitalization
and confirmed as diabetes after hospitalization by standard
diagnostic criteria but unrecognized as diabetes by the
treating physician during hospitalization.
- Hospital-related
hyperglycemia: hyperglycemia (fasting blood glucose 126
mg/dl or random blood glucose 200 mg/dl) occurring during
the hospitalization that reverts to normal after hospital
discharge.
The
prevalence of diabetes in hospitalized adult patients is not
precisely known. In the year 2000, 12.4% of hospital discharges
in the U.S. listed diabetes as a diagnosis. The prevalence
of diabetes in hospitalized adults is conservatively estimated
at 1225%, depending on the thoroughness used in identifying
patients. Patients presenting to hospitals may have diabetes,
unrecognized diabetes, or hospital-related hyperglycemia.
Using the A1C test may be a valuable case-finding tool for
identifying diabetes in hospitalized patients.
A
rapidly growing body of literature supports targeted glucose
control in the hospital setting with potential for improved
mortality, morbidity, and health care economic outcomes. Hyperglycemia
in the hospital may result from stress, decompensation of
type 1 diabetes, type 2 diabetes, or other forms of diabetes
and/or may be iatrogenic due to administration or withholding
of pharmacologic agents, including glucocorticoids, vasopressors,
etc. Distinction between decompensated diabetes and stress
hyperglycemia is often not made.
1.
Blood glucose targets
a.
General medicine and surgery.
Observational
studies suggest an association between hyperglycemia and increased
mortality. General medical and surgical patients with a blood
glucose value(s) >220 mg/dl (12.2 mmol/l) have higher infection
rates.
When
admissions on general medicine and surgery units were studied,
patients with new hyperglycemia had significantly increased
inhospital mortality, as did patients with known diabetes.
In addition, length of stay was higher for the new hyperglycemic
group, and both the patients with new hyperglycemia and those
with known diabetes were more likely to require intensive
care unit (ICU) care and transitional or nursing home care.
Better outcomes were demonstrated in patients with fasting
and admission blood glucose <126 mg/dl (7 mmol/l) and all
random blood glucose levels <200 mg/dl (11.1 mmol/l).
b.
CVD and critical care.
The
relationship of blood glucose levels and mortality in the
setting of acute myocatdial infarction (AMI) has been reported.
A meta-analysis of 15 previously published studies compared
in-hospital mortality and CHF in both hyper- and normoglycemic
patients with and without diabetes. In subjects without known
diabetes whose admission blood glucose was 109.8 mg/dl (6.1
mmol/l), the relative risk for in-hospital mortality was increased
significantly. When diabetes was present and admission glucose
180 mg/dl (10 mmol/l), risk of death was moderately increased
compared with patients who had diabetes but no hyperglycemia
on admission. In another study, admission blood glucose values
were analyzed in consecutive patients with AMI. Analysis revealed
an independent association of admission blood glucose and
mortality. The 1-year mortality rate was significantly lower
in subjects with admission plasma glucose <100.8 mg/dl
(5.6 mmol/l) than in those with plasma glucose 199.8 mg/dl
(11 mmol/l).
Finally,
in the first Diabetes and Insulin-Glucose Infusion in Acute
Myocardial Infarction (DIGAMI) study, insulin-glucose infusion
followed by subcutaneous insulin treatment in diabetic patients
with AMI was examined. Intensive subcutaneous insulin therapy
for 3 months improved long-term survival. Mean blood glucose
in the intensive insulin intervention arm was 172.8 mg/dl
(9.6 mmol/l) (compared with 210.6 mg/dl [11.7 mmol/l] in the
"conventional" group). The broad range of blood
glucose levels within each arm limits the ability to define
specific blood glucose target thresholds.
c.
Cardiac surgery.
Attainment
of targeted glucose control in the setting of cardiac surgery
is associated with reduced mortality and risk of deep sternal
wound infections in cardiac surgery patients with diabetes
and supports the concept that perioperative hyperglycemia
is an independent predictor of infection in patients with
diabetes , with the lowest mortality in patients with blood
glucose <150 mg/dl (8.3 mmol/l).
d.
Critical care.
A
mixed group of patients with and without diabetes admitted
to a surgical ICU were randomized to receive intensive insulin
therapy (target blood glucose 80110 mg/dl [4.46.1
mmol/l]). The mean blood glucose of 103 mg/dl (5.7 mmol/l)
had reduced mortality during the ICU stay and decreased overall
in-hospital mortality. Subsequent analysis demonstrated that
for each 20 mg/dl (1.1 mmol/l) glucose was elevated above
100 mg/dl (5.5 mmol/l), the risk of ICU death increased. Hospital
and ICU survival were linearly associated with ICU glucose
levels, with the highest survival rates occurring in patients
achieving an average blood glucose <110 mg/dl (6.1 mmol/l).
e.
Acute neurological disorders.
Hyperglycemia
is associated with worsened outcomes in patients with acute
stroke and head injury, as evidenced by the large number of
observational studies in the literature. A meta-analysis identified
an admission blood glucose >110 mg/dl (6.1 mmol/l) for
increased mortality for acute stroke.
2.
Treatment options
a.
Oral diabetes agents.
No
large studies have investigated the potential roles of various
oral agents on outcomes in hospitalized patients with diabetes.
While the various classes of oral agents are commonly used
in the outpatient setting with good response, their use in
the inpatient setting presents some specific issues.
i.
Sulfonylureas and meglitinides. The long action
and predisposition to hypoglycemia in patients not consuming
their normal nutrition serve as relative contraindications
to routine use of sulfonylureas in the hospital for many patients.
Sulfonylureas do not generally allow rapid dose adjustment
to meet the changing inpatient needs. Sulfonylureas also vary
in duration of action between individuals and likely vary
in the frequency with which they induce hypoglycemia. While
the two available meglitinides, repaglinide and neteglinide,
theoretically would produce less hypoglycemia than sulfonylureas,
lack of clinical trial data for these agents would preclude
their use.
ii.
Metformin. The major limitation to metformin
use in the hospital is a number of specific contraindications
to its use, many of which occur in the hospital. All of these
contraindications relate to lactic acidosis, a potentially
fatal complication of metformin therapy. The most common risk
factors for lactic acidosis in metformin-treated patients
are cardiac disease, including CHF, hypoperfusion, renal insufficiency,
old age, and chronic pulmonary disease. Recent evidence continues
to indicate lactic acidosis is a rare complication, despite
the relative frequency of risk factors. However, in the hospital,
where the risk for hypoxia, hypoperfusion, and renal insufficiency
is much higher, it still seems prudent to avoid the use of
metformin in most patients.
iii.
TZDs. TZDs are not suitable for initiation in
the hospital because of their delayed onset of effect. In
addition, they do increase intravascular volume, a particular
problem in those predisposed to CHF and potentially a problem
for patients with hemodynamic changes related to admission
diagnoses (e.g., acute coronary ischemia) or interventions
common in hospitalized patients.
In
summary, each of the major classes of oral agents has significant
limitations for inpatient use. Additionally, they provide
little flexibility or opportunity for titration in a setting
where acute changes demand these characteristics. Therefore,
insulin, when used properly, may have many advantages in the
hospital setting.
b.
Insulin.
The
inpatient insulin regimen must be matched or tailored to the
specific clinical circumstance of the individual patient.
A recent meta-analysis concluded that insulin therapy in critically
ill patients had a beneficial effect on short-term mortality
in different clinical settings.
i.
Subcutaneous insulin therapy. Subcutaneous insulin
therapy may be used to attain glucose control in most hospitalized
patients with diabetes. The components of the daily insulin
dose requirement can be met by a variety of insulins, depending
on the particular hospital situation. Subcutaneous insulin
therapy is subdivided into programmed or scheduled insulin
and supplemental or correction-dose insulin. Correction-dose
insulin therapy is an important adjunct to scheduled insulin,
both as a dose-finding strategy and as a supplement when rapid
changes in insulin requirements lead to hyperglycemia. If
correction doses are frequently required, it is recommended
that the appropriate scheduled insulin doses be increased
the following day to accommodate the increased insulin needs.
There are no studies comparing human regular insulin with
rapid-acting analogs for use as correction-dose insulin. However,
due to the longer duration with human regular insulin, there
is a greater risk of "insulin stacking" when the
usual next blood glucose measurement is performed 46
h later.
The
traditional sliding-scale insulin regimens, usually consisting
of regular insulin without any intermediate or long-acting
insulins, have been shown to be ineffective. Problems cited
with sliding-scale insulin regimens are that the sliding-scale
regimen prescribed on admission is likely to be used throughout
the hospital stay without modification. Second, sliding-scale
insulin therapy treats hyperglycemia after it has already
occurred, instead of preventing the occurrence of hyperglycemia.
This "reactive" approach can lead to rapid changes
in blood glucose levels, exacerbating both hyper- and hypoglycemia.
ii.
Intravenous insulin infusion. The only method
of insulin delivery specifically developed for use in the
hospital is continuous intravenous infusion, using regular
crystalline insulin. There is no advantage to using insulin
lispro or aspart in an intravenous insulin infusion. The medical
literature supports the use of intravenous insulin infusion
in preference to the subcutaneous route of insulin administration
for several clinical indications among nonpregnant adults.
These include DKA and nonketotic hyperosmolar state; general
preoperative, intraoperative, and postoperative care; the
postoperative period following heart surgery; following organ
transplantation; with cardiogenic shock; exacerbated hyperglycemia
during high-dose glucocorticoid therapy; patients who are
not eating (NPO) or in critical care illness in general; and
as a dose-finding strategy in anticipation of initiation or
reinitiation of subcutaneous insulin therapy in type 1 or
type 2 diabetes.
Many
institutions use insulin infusion algorithms that can be implemented
by nursing staff. Algorithms should incorporate the concept
that maintenance requirements differ between patients and
change over the course of treatment. Although numerous algorithms
have been published, there have been no head-to-head comparisons,
and thus no single algorithm can be recommended for an individual
hospital. Ideally, intravenous insulin algorithms should consider
both the glucose level and its rate of change. For all algorithms,
frequent bedside glucose testing is required but the ideal
frequency is not known.
iii.
Transition from intravenous to subcutaneous insulin
therapy. There are no specific clinical trials examining
how to best transition from intravenous to subcutaneous insulin
or which patients with type 2 diabetes may be transitioned
to oral agents. For those who will require subcutaneous insulin,
it is necessary to administer short- or rapid-acting insulin
subcutaneously 12 h before discontinuation of the intravenous
insulin infusion. An intermediate- or long-acting insulin
must be injected 23 h before discontinuing the insulin
infusion. In transitioning from intravenous insulin infusion
to subcutaneous therapy, the caregiver may order subcutaneous
insulin with appropriate duration of action to be administered
as a single dose or repeatedly to maintain basal effect until
the time of day when the choice of insulin or analog preferred
for basal effect normally would be provided.
3.
Self-management in the hospital
Self-management
in the hospital may be appropriate for competent adult patients
who have a stable level of consciousness and reasonably stable
known daily insulin requirements and successfully conduct
self-management of diabetes at home, have physical skills
appropriate to successfully self-administer insulin, perform
SMBG, and have adequate oral intake. Appropriate patients
are those already proficient in carbohydrate counting, use
of multiple daily injections of insulin or insulin pump therapy,
and sick-day management. The patient and physician in consultation
with nursing staff must agree that patient self-management
is appropriate under the conditions of hospitalization.
4.
Preventing hypoglycemia
Hypoglycemia,
especially in insulin-treated patients, is the leading limiting
factor in the glycemic management of type 1 and type 2 diabetes.
In the hospital, multiple additional risk factors for hypoglycemia
are present, even among patients who are neither "brittle"
nor tightly controlled. Patients who do not have diabetes
may experience hypoglycemia in the hospital, in association
with factors such as altered nutritional state, heart failure,
renal or liver disease, malignancy, infection, or sepsis.
Patients having diabetes may develop hypoglycemia in association
with the same conditions. Additional triggering events leading
to iatrogenic hypoglycemia include sudden reduction of corticosteroid
dose, altered ability of the patient to self-report symptoms,
reduction of oral intake, emesis, new NPO status, reduction
of rate of administration of intravenous dextrose, and unexpected
interruption of enteral feedings or parenteral nutrition.
Altered consciousness from anesthesia may also alter typical
hypoglycemic symptoms.
Despite
the preventable nature of many inpatient episodes of hypoglycemia,
institutions are more likely to have nursing protocols for
the treatment of hypoglycemia than for its prevention.
5.
Diabetes care providers
Diabetes
management may be effectively offered by primary care physicians
or hospitalists, but involvement of appropriately trained
specialists or specialty teams may reduce length of stay,
improve glycemic control, and improve outcomes. In the care
of diabetes, implementation of standardized order sets for
scheduled and correction-dose insulin may reduce reliance
on sliding-scale management. A team approach is needed to
establish hospital pathways. To implement intravenous infusion
of insulin for the majority of patients having prolonged NPO
status, hospitals will need multidisciplinary support for
using insulin infusion therapy outside of critical care units.
6.
DSME
Teaching
diabetes self-management to patients in hospitals is a difficult
and challenging task. Patients are hospitalized because they
are ill, are under increased stress related to their hospitalization
and diagnosis, and are in an environment that is not conducive
to learning Ideally, people with diabetes should be taught
at a time and place conducive to learning: as an outpatient
in a nationally recognized program of diabetes education classes.
For
the hospitalized patient, diabetes "survival skills"
education is generally considered a feasible approach. Patients
are taught sufficient information to enable them to go home
safely. Those newly diagnosed with diabetes or who are new
to insulin and or blood glucose monitoring need to be instructed
before discharge to help ensure safe care upon returning home.
Those patients hospitalized because of a crisis related to
diabetes management or poor care at home need education to
hopefully prevent subsequent episodes of hospitalization.
7.
MNT
Even
though hospital diets continue to be ordered by calorie levels
based on the "ADA diet," it has been recommended
that the term "ADA diet" no longer be used. Since
1994, the ADA has not endorsed any single meal plan or specified
percentages of macronutrients. Current nutrition recommendations
advise individualization based on treatment goals, physiologic
parameters, and medication usage.
Because
of the complexity of nutrition issues, it is recommended that
a registered dietitian, knowledgeable and skilled in MNT,
serve as the team member who provides MNT. The dietitian is
responsible for integrating information about the patients
clinical condition, eating, and lifestyle habits and for establishing
treatment goals in order to determine a realistic plan for
nutrition therapy.
8.
Bedside blood glucose monitoring
Implementing
intensive diabetes therapy in the hospital setting requires
frequent and accurate blood glucose data. This measure is
analogous to an additional "vital sign" for hospitalized
patients with diabetes. Bedside glucose monitoring using capillary
blood has advantages over laboratory venous glucose testing
because the results can be obtained rapidly at the "point
of care," where therapeutic decisions are made. For this
reason, the terms bedside and point-of-care glucose monitoring
are used interchangeably.
For
patients who are eating, commonly recommended testing frequencies
are premeal and at bedtime. For patients not eating, testing
every 46 h is usually sufficient for determining correction
insulin doses. Patients controlled with continuous intravenous
insulin typically require hourly blood glucose testing until
the blood glucose levels are stable, then every 2 h.
Bedside
blood glucose testing is usually performed with portable glucose
devices that are identical or similar to devices for home
SMBG.
B.
Diabetes care in the school and day care setting
Recommendations
- An
individualized diabetes medical management plan (DMMP) should
be developed by the parent/guardian and the students
diabetes health care team. (E)
- An
adequate number of school personnel should be trained in
the necessary diabetes procedures (including monitoring
of blood glucose levels and administration of insulin and
glucagon) and in the appropriate response to high and low
blood glucose levels. These school personnel need not be
health care professionals. (E)
- The
student with diabetes should have immediate access to diabetes
supplies at all times, with supervision as needed. (E)
- The
student should be permitted to monitor his or her blood
glucose level and take appropriate action to treat hypoglycemia
in the classroom or anywhere the student is in conjunction
with a school activity if indicated in the students
DMMP. (E)
There
are 206,000 individuals <20 years of age with diabetes
in the U.S., most of whom attend school and/or some type of
day care and need knowledgeable staff to provide a safe environment.
Despite legal protections, children in the school and day
care setting still face discrimination. Parents and the health
care team should provide school systems and day care providers
with the information necessary by developing an individualized
DMMP, including information necessary for children with diabetes
to participate fully and safely in the school/day care experience.
Appropriate diabetes care in the school and day care setting
is necessary for the childs immediate safety, long-term
well-being, and optimal academic performance.
An
adequate number of school personnel should be trained in the
necessary diabetes procedures (e.g., blood glucose monitoring
and insulin and glucagon administration) and in the appropriate
response to high and low blood glucose levels. This will ensure
that at least one adult is present to perform these procedures
in a timely manner while the student is at school, on field
trips, and during extracurricular activities or other school-sponsored
events. These school personnel need not be health care professionals.
The
student with diabetes should have immediate access to diabetes
supplies at all times, with supervision as needed. A student
with diabetes should be able to obtain a blood glucose level
and respond to the results as quickly and conveniently as
possible, minimizing the need for missing instruction in the
classroom. Accordingly, a student who is capable of doing
so should be permitted to monitor his or her blood glucose
level and take appropriate action to treat hypoglycemia in
the classroom or anywhere the student is in conjunction with
a school activity. The students desire for privacy during
testing and should also be accommodated.
C.
Diabetes care at diabetes camps
Recommendations
- Each
camper should have a standardized medical form completed
by his/her family and the physician managing the diabetes.
(E)
- It
is imperative that the medical staff is led by someone with
expertise in managing type 1 and type 2 diabetes and includes
a nursing staff (including diabetes educators and diabetes
clinical nurse specialists) and registered dietitians with
expertise in diabetes. (E)
- All
camp staff, including medical, nursing, nutrition, and volunteer,
should undergo background testing to ensure appropriateness
in working with children. (E)
The
concept of specialized residential and day camps for children
with diabetes has become widespread throughout the U.S. and
many other parts of the world. The mission of camps specialized
for children and youth with diabetes is to allow for a camping
experience in a safe environment. An equally important goal
is to enable children with diabetes to meet and share their
experiences with one another while they learn to be more personally
responsible for their disease. For this to occur, a skilled
medical and camping staff must be available to ensure optimal
safety and an integrated camping/educational experience.
The
diabetes camping experience is short term and is most often
associated with increased physical activity relative to that
experienced while at home. Thus, goals of glycemic control
are more related to the avoidance of extremes in blood glucose
levels than to the optimization of intensive glycemic control
while away at camp.
Each
camper should have a standardized medical form completed by
his/her family and the physician managing the diabetes that
details the campers past medical history, immunization
record, and diabetes regimen. The home insulin dosage should
be recorded for each camper, including number and timing of
injections or basal and bolus dosages given by continuous
subcutaneous insulin infusion and type(s) of insulin used.
During
camp, a daily record of the campers progress should
be made. All blood glucose levels and insulin dosages should
be recorded. To ensure safety and optimal diabetes management,
multiple blood glucose determinations should be made throughout
each 24-h period: before meals, at bedtime, after or during
prolonged and strenuous activity, and in the middle of the
night when indicated for prior hypoglycemia. If major alterations
of a campers regimen appear to be indicated, it is important
to discuss this with the camper and the family in addition
to the childs local physician. The record of what transpired
during camp should be discussed with the family when the camper
is picked up.
A
formal relationship with a nearby medical facility should
be secured for each camp so that camp medical staff have the
ability to refer to this facility for prompt treatment of
medical emergencies. It is imperative that the medical staff
is led by someone with expertise in managing type 1 and type
2 diabetes. Nursing staff should include diabetes educators
and diabetes clinical nurse specialists. Registered dietitians
with expertise in diabetes should also have input into the
design of the menu and the education program. All camp staff,
including medical, nursing, nutrition, and volunteer, should
undergo background testing to ensure appropriateness in working
with children.
D.
Diabetes management in correctional institutions
Recommendations
- Patients
with a diagnosis of diabetes should have a complete medical
history and undergo an intake physical examination by a
licensed health professional in a timely manner. (E)
- Insulin-treated
patients should have a capillary blood glucose (CBG) determination
within 12 h of arrival. (E)
- Medications
and MNT should be continued without interruption upon entry
into the correctional environment. (E)
- Correctional
staff should be trained in the recognition, treatment, and
appropriate referral for hypo- and hyperglycemia. (E)
- Train
staff to recognize symptoms and signs of serious metabolic
decompensation and to immediately refer the patient for
appropriate medical care. (E)
- Institutions
should implement a policy requiring staff to notify a physician
of all CBG results outside of a specified range, as determined
by the treating physician. (E)
- Identify
patients with type 1 diabetes who are at high risk for DKA.
(E)
- In
the correctional setting, policies and procedures need to
be developed and implemented to enable CBG monitoring to
occur at the frequency necessitated by the individual patients
glycemic control and diabetes regimen. (E)
- Include
diabetes in correctional staff education programs. (E)
- For
all interinstitutional transfers, complete a medical transfer
summary to be transferred with the patient. (E)
- Diabetes
supplies and medication should accompany the patient during
transfer. (E)
- Begin
discharge planning with adequate lead time to insure continuity
of care and facilitate entry into community diabetes care.
(E)
At
any given time, >2 million people are incarcerated in prisons
and jails in the U.S. It is estimated that nearly 80,000 of
these inmates have diabetes. In addition, many more people
with diabetes pass through the corrections system in a given
year.
People
with diabetes in correctional facilities should receive care
that meets national standards. Correctional institutions have
unique circumstances that need to be considered so that all
standards of care may be achieved. Correctional institutions
should have written policies and procedures for the management
of diabetes and for training of medical and correctional staff
in diabetes care practices.
Reception
screening should emphasize patient safety. In particular,
rapid identification of all insulin-treated individuals with
diabetes is essential in order to identify those at highest
risk for hypo- and hyperglycemia and DKA. All insulin-treated
patients should have a CBG determination within 12 h
of arrival. Patients with a diagnosis of diabetes should have
a complete medical history and physical examination by a licensed
health care provider with prescriptive authority in a timely
manner. It is essential that medication and MNT be continued
without interruption upon entry into the correctional system,
as a hiatus in either medication or appropriate nutrition
may lead to either severe hypo- or hyperglycemia.
All
patients must have access to prompt treatment of hypo- and
hyperglycemia. Correctional staff should be trained in the
recognition and treatment of hypo- and hyperglycemia, and
appropriate staff should be trained to administer glucagon.
Institutions should implement a policy requiring staff to
notify a physician of all CBG results outside of a specified
range, as determined by the treating physician.
Correctional
institutions should have systems in place to ensure that insulin
administration and meals are coordinated to prevent hypo-
and hyperglycemia, taking into consideration the transport
of residents off site and the possibility of emergency schedule
changes.
Monitoring
of CBG is a strategy that allows caregivers and people with
diabetes to evaluate diabetes management regimens. The frequency
of monitoring will vary by patients glycemic control
and diabetes regimens. Policies and procedures should be implemented
to ensure that the health care staff has adequate knowledge
and skills to direct the management and education of individuals
with diabetes.
Patients
in jails may be housed for a short period of time before being
transferred or released, and it is not unusual for patients
in prison to be transferred within the system several times
during their incarceration. Transferring a patient with diabetes
from one correctional facility to another requires a coordinated
effort as does planning for discharge.
|
IX.
HYPOGLYCEMIA AND EMPLOYMENT/LICENSURE
|
Recommendations
- People
with diabetes should be individually considered for employment
based on the requirements of the specific job and the individuals
medical condition, treatment regimen, and medical history.
(E)
Any
person with diabetes, whether insulin treated or noninsulin
treated, should be eligible for any employment for which he/she
is otherwise qualified. Despite the significant medical and
technological advances made in managing diabetes, discrimination
in employment and licensure against people with diabetes still
occurs. This discrimination is often based on apprehension
that the person with diabetes may present a safety risk to
the employer or the public, a fear sometimes based on misinformation
or lack of up-to-date knowledge about diabetes. Perhaps the
greatest concern is that hypoglycemia will cause sudden unexpected
incapacitation. However, most people with diabetes can manage
their condition in such a manner that there is minimal risk
of incapacitation from hypoglycemia.
Because
the effects of diabetes are unique to each individual, it
is inappropriate to consider all people with diabetes the
same. People with diabetes should be individually considered
for employment based on the requirements of the specific job.
Factors to be weighed in this decision include the individuals
medical condition, treatment regimen (MNT, oral glucose-lowering
agent, and/or insulin), and medical history, particularly
in regard to the occurrence of incapacitating hypoglycemic
episodes.
|
X. THIRD-PARTY REIMBURSEMENT FOR DIABETES CARE,
SELF-MANAGEMENT EDUCATION, AND SUPPLIES
|
Recommendations
- Patients
and practitioners should have access to all classes of antidiabetic
medications, equipment, and supplies without undue controls.
(E)
- MNT
and DSME should be covered by insurance and other payors.
(E)
To
achieve optimal glucose control, the person with diabetes
must be able to access health care providers who have expertise
in the field of diabetes. Treatments and therapies that improve
glycemic control and reduce the complications of diabetes
will also significantly reduce health care costs. Access to
the integral components of diabetes care, such as health care
visits, diabetes supplies and medications, and self-management
education, is essential. All medications and supplies, such
as syringes, strips, and meters, related to the daily care
of diabetes must also be reimbursed by third-party payors.
It
is recognized that the use of formularies, prior authorization,
and related provisions, such as competitive bidding, can manage
provider practices as well as costs to the potential benefit
of payors and patients. However, any controls should ensure
that all classes of antidiabetic agents with unique mechanisms
of action and all classes of equipment and supplies designed
for use with such equipment are available to facilitate achieving
glycemic goals and to reduce the risk of complications. To
reach diabetes treatment goals, practitioners should have
access to all classes of antidiabetic medications, equipment,
and supplies without undue controls. Without appropriate safeguards,
these controls could constitute an obstruction of effective
care.
Medicare
and many other third-party payors cover DSME (diabetes self-management
training [DSMT]) and MNT. The qualified beneficiary, who meets
the diagnostic criteria and medical necessity, can receive
an initial benefit of 10 h of DSMT and 3 h of MNT with a potential
total of 13 h of initial education as long as the services
are not provided on the same date. However, not all Medicare
beneficiaries with a diagnosis of diabetes will qualify for
both MNT and DSMT benefits. More information on Medicare policy,
including follow-up benefits, is available at http://www.diabetes.org/for-health-professionals-and-scientists/recognition/dsmt-mntfaqs.jsp
|
XI.
STRATEGIES FOR IMPROVING DIABETES CARE
|
The
implementation of the standards of care for diabetes has been
suboptimal in most clinical settings. A recent report (24)
indicated that only 37% of adults with diagnosed diabetes
achieved an A1C of <7%, only 36% had a blood pressure <130/80
mmHg, and just 48% had a cholesterol <200 mg/dl. Most distressing
was that only 7.3% of diabetes subjects achieved all three
treatment goals.
While
numerous interventions to improve adherence to the recommended
standards have been implemented, the challenge of providing
uniformly effective diabetes care has thus far defied a simple
solution. A major contributor to suboptimal care is a delivery
system that too often is fragmented, lacks clinical information
capabilities, often duplicates services, and is poorly designed
for the delivery of chronic care. The Institute of Medicine
has called for changes so that delivery systems provide care
that is evidence based, patient centered, and systems oriented
and takes advantage of information technologies that foster
continuous quality improvement. Collaborative, multidisciplinary
teams should be best suited to provide such care for people
with chronic conditions like diabetes and to empower patients
performance of appropriate self-management. Alterations in
reimbursement that reward the provision of quality care, as
defined by the attainment of quality measures developed by
such activities as the ADA/National Committee for Quality
Assurance Diabetes Provider Recognition Program will also
be required to achieve desired outcome goals.
The
National Diabetes Education Program recently launched a new
online resource to help health care professionals better organize
their diabetes care. The www.betterdiabetescare.nih.gov website
should help users design and implement more effective health
care delivery systems for those with diabetes.
In
recent years, numerous health care organizations, ranging
from large health care systems such as the U.S. Veterans
Administration to small private practices, have implemented
strategies to improve diabetes care. Successful programs have
published results showing improvement in important outcomes
such as A1C measurements and blood pressure and lipid determinations
as well as process measures such as provision of eye exams.
Successful interventions have been focused at the level of
health care professionals, delivery systems, and patients.
Features of successful programs reported in the literature
include:
- Improving
health care professional education regarding the standards
of care through formal and informal education programs.
- Delivery
of DSME, which has been shown to increase adherence to standard
of care.
- Adoption
of practice guidelines, with participation of health care
professionals in the process. Guidelines should be readily
accessible at the point of service, such as on patient charts,
in examining rooms, in "wallet or pocket cards,"
on PDAs, or on office computer systems. Guidelines should
begin with a summary of their major recommendations instructing
health care professionals what to do and how to do it.
- Use
of checklists that mirror guidelines have been successful
at improving adherence to standards of care.
- Systems
changes, such as provision of automated reminders to health
care professionals and patients, reporting of process and
outcome data to providers, and especially identification
of patients at risk because of failure to achieve target
values or a lack of reported values.
- Quality
improvement programs combining continuous quality improvement
or other cycles of analysis and intervention with provider
performance data.
- Practice
changes, such as clustering of dedicated diabetes visits
into specific times within a primary care practice schedule
and/or visits with multiple health care professionals on
a single day and group visits.
- Tracking
systems with either an electronic medical record or patient
registry have been helpful at increasing adherence to standards
of care by prospectively identifying those requiring assessments
and/or treatment modifications. They likely could have greater
efficacy if they suggested specific therapeutic interventions
to be considered for a particular patient at a particular
point in time (225).
- A
variety of nonautomated systems, such as mailing reminders
to patients, chart stickers, and flow sheets, have been
useful to prompt both providers and patients.
- Availability
of case or (preferably) care management services, usually
by a nurse. Nurses, pharmacists, and other nonphysician
health care professionals using detailed algorithms working
under the supervision of physicians and/or nurse education
calls have also been helpful. Similarly dietitians using
MNT guidelines have been demonstrated to improve glycemic
control.
- Availability
and involvement of expert consultants, such as endocrinologists
and diabetes educators.
Evidence suggests that these individual initiatives work
best when provided as components of a multifactorial intervention.
Therefore, it is difficult to assess the contribution of
each component; however, it is clear that optimal diabetes
management requires an organized, systematic approach and
involvement of a coordinated team of health care professionals.
|
Diagnosis and Classification of Diabetes Mellitus
|
American
Diabetes Association
Abbreviations: FPG, fasting plasma glucose GAD,
glutamic acid decarboxylase GCT, glucose challenge
test GDM, gestational diabetes mellitus HNF,
hepatocyte nuclear factor IFG, impaired fasting glucose
IGT, impaired glucose tolerance MODY, maturity-onset
diabetes of the young WHO, World Health Organization
DEFINITION
AND DESCRIPTION OF DIABETES MELLITUS
Diabetes
mellitus is a group of metabolic diseases characterized by
hyperglycemia resulting from defects in insulin secretion,
insulin action, or both. The chronic hyperglycemia of diabetes
is associated with long-term damage, dysfunction, and failure
of various organs, especially the eyes, kidneys, nerves, heart,
and blood vessels.
Several
pathogenic processes are involved in the development of diabetes.
These range from autoimmune destruction of the ß-cells
of the pancreas with consequent insulin deficiency to abnormalities
that result in resistance to insulin action. The basis of
the abnormalities in carbohydrate, fat, and protein metabolism
in diabetes is deficient action of insulin on target tissues.
Deficient insulin action results from inadequate insulin secretion
and/or diminished tissue responses to insulin at one or more
points in the complex pathways of hormone action. Impairment
of insulin secretion and defects in insulin action frequently
coexist in the same patient, and it is often unclear which
abnormality, if either alone, is the primary cause of the
hyperglycemia.
Symptoms
of marked hyperglycemia include polyuria, polydipsia, weight
loss, sometimes with polyphagia, and blurred vision. Impairment
of growth and susceptibility to certain infections may also
accompany chronic hyperglycemia. Acute, life-threatening consequences
of uncontrolled diabetes are hyperglycemia with ketoacidosis
or the nonketotic hyperosmolar syndrome.
Long-term
complications of diabetes include retinopathy with potential
loss of vision; nephropathy leading to renal failure; peripheral
neuropathy with risk of foot ulcers, amputations, and Charcot
joints; and autonomic neuropathy causing gastrointestinal,
genitourinary, and cardiovascular symptoms and sexual dysfunction.
Patients with diabetes have an increased incidence of atherosclerotic
cardiovascular, peripheral arterial, and cerebrovascular disease.
Hypertension and abnormalities of lipoprotein metabolism are
often found in people with diabetes.
The
vast majority of cases of diabetes fall into two broad etiopathogenetic
categories (discussed in greater detail below). In one category,
type 1 diabetes, the cause is an absolute deficiency of insulin
secretion. Individuals at increased risk of developing this
type of diabetes can often be identified by serological evidence
of an autoimmune pathologic process occurring in the pancreatic
islets and by genetic markers. In the other, much more prevalent
category, type 2 diabetes, the cause is a combination of resistance
to insulin action and an inadequate compensatory insulin secretory
response. In the latter category, a degree of hyperglycemia
sufficient to cause pathologic and functional changes in various
target tissues, but without clinical symptoms, may be present
for a long period of time before diabetes is detected. During
this asymptomatic period, it is possible to demonstrate an
abnormality in carbohydrate metabolism by measurement of plasma
glucose in the fasting state or after a challenge with an
oral glucose load.
The
degree of hyperglycemia (if any) may change over time, depending
on the extent of the underlying disease process (Fig. 1).
A disease process may be present but may not have progressed
far enough to cause hyperglycemia. The same disease process
can cause impaired fasting glucose (IFG) and/or impaired glucose
tolerance (IGT) without fulfilling the criteria for the diagnosis
of diabetes. In some individuals with diabetes, adequate glycemic
control can be achieved with weight reduction, exercise, and/or
oral glucose-lowering agents. These individuals therefore
do not require insulin. Other individuals who have some residual
insulin secretion but require exogenous insulin for adequate
glycemic control can survive without it. Individuals with
extensive ß-cell destruction and therefore no residual
insulin secretion require insulin for survival. The severity
of the metabolic abnormality can progress, regress, or stay
the same. Thus, the degree of hyperglycemia reflects the severity
of the underlying metabolic process and its treatment more
than the nature of the process itself.
Figure
1 Disorders of glycemia: etiologic types and stages.
*Even after presenting in ketoacidosis, these patients can
briefly return to normoglycemia without requiring continuous
therapy (i.e., "honeymoon" remission); **in rare
instances, patients in these categories (e.g., Vacor toxicity,
type 1 diabetes presenting in pregnancy) may require insulin
for survival.
CLASSIFICATION
OF DIABETES MELLITUS AND OTHER CATEGORIES OF GLUCOSE REGULATION
Assigning a type of diabetes to an individual often depends
on the circumstances present at the time of diagnosis, and
many diabetic individuals do not easily fit into a single
class. For example, a person with gestational diabetes mellitus
(GDM) may continue to be hyperglycemic after delivery and
may be determined to have, in fact, type 2 diabetes. Alternatively,
a person who acquires diabetes because of large doses of exogenous
steroids may become normoglycemic once the glucocorticoids
are discontinued, but then may develop diabetes many years
later after recurrent episodes of pancreatitis. Another example
would be a person treated with thiazides who develops diabetes
years later. Because thiazides in themselves seldom cause
severe hyperglycemia, such individuals probably have type
2 diabetes that is exacerbated by the drug. Thus, for the
clinician and patient, it is less important to label the particular
type of diabetes than it is to understand the pathogenesis
of the hyperglycemia and to treat it effectively.
Type
1 diabetes (ß-cell destruction, usually leading to absolute
insulin deficiency) Immune-mediated diabetes.
This
form of diabetes, which accounts for only 510% of those
with diabetes, previously encompassed by the terms insulin-dependent
diabetes, type I diabetes, or juvenile-onset diabetes, results
from a cellular-mediated autoimmune destruction of the ß-cells
of the pancreas. Markers of the immune destruction of the
ß-cell include islet cell autoantibodies, autoantibodies
to insulin, autoantibodies to glutamic acid decarboxylase
(GAD65), and autoantibodies to the tyrosine phosphatases IA-2
and IA-2ß. One and usually more of these autoantibodies
are present in 8590% of individuals when fasting hyperglycemia
is initially detected. Also, the disease has strong HLA associations,
with linkage to the DQA and DQB genes, and it is influenced
by the DRB genes. These HLA-DR/DQ alleles can be either predisposing
or protective.
In
this form of diabetes, the rate of ß-cell destruction
is quite variable, being rapid in some individuals (mainly
infants and children) and slow in others (mainly adults).
Some patients, particularly children and adolescents, may
present with ketoacidosis as the first manifestation of the
disease. Others have modest fasting hyperglycemia that can
rapidly change to severe hyperglycemia and/or ketoacidosis
in the presence of infection or other stress. Still others,
particularly adults, may retain residual ß-cell function
sufficient to prevent ketoacidosis for many years; such individuals
eventually become dependent on insulin for survival and are
at risk for ketoacidosis. At this latter stage of the disease,
there is little or no insulin secretion, as manifested by
low or undetectable levels of plasma C-peptide. Immune-mediated
diabetes commonly occurs in childhood and adolescence, but
it can occur at any age, even in the 8th and 9th decades of
life.
Autoimmune
destruction of ß-cells has multiple genetic predispositions
and is also related to environmental factors that are still
poorly defined. Although patients are rarely obese when they
present with this type of diabetes, the presence of obesity
is not incompatible with the diagnosis. These patients are
also prone to other autoimmune disorders such as Graves
disease, Hashimotos thyroiditis, Addisons disease,
vitiligo, celiac sprue, autoimmune hepatitis, myasthenia gravis,
and pernicious anemia.
Idiopathic
diabetes.
Some
forms of type 1 diabetes have no known etiologies. Some of
these patients have permanent insulinopenia and are prone
to ketoacidosis, but have no evidence of autoimmunity. Although
only a minority of patients with type 1 diabetes fall into
this category, of those who do, most are of African or Asian
ancestry. Individuals with this form of diabetes suffer from
episodic ketoacidosis and exhibit varying degrees of insulin
deficiency between episodes. This form of diabetes is strongly
inherited, lacks immunological evidence for ß-cell autoimmunity,
and is not HLA associated. An absolute requirement for insulin
replacement therapy in affected patients may come and go.
Type
2 diabetes (ranging from predominantly insulin resistance
with relative insulin deficiency to predominantly an insulin
secretory defect with insulin resistance)
This
form of diabetes, which accounts for 9095% of those
with diabetes, previously referred to as non-insulin-dependent
diabetes, type II diabetes, or adult-onset diabetes, encompasses
individuals who have insulin resistance and usually have relative
(rather than absolute) insulin deficiency At least initially,
and often throughout their lifetime, these individuals do
not need insulin treatment to survive. There are probably
many different causes of this form of diabetes. Although the
specific etiologies are not known, autoimmune destruction
of ß-cells does not occur, and patients do not have
any of the other causes of diabetes listed above or below.
Most
patients with this form of diabetes are obese, and obesity
itself causes some degree of insulin resistance. Patients
who are not obese by traditional weight criteria may have
an increased percentage of body fat distributed predominantly
in the abdominal region. Ketoacidosis seldom occurs spontaneously
in this type of diabetes; when seen, it usually arises in
association with the stress of another illness such as infection.
This form of diabetes frequently goes undiagnosed for many
years because the hyperglycemia develops gradually and at
earlier stages is often not severe enough for the patient
to notice any of the classic symptoms of diabetes. Nevertheless,
such patients are at increased risk of developing macrovascular
and microvascular complications. Whereas patients with this
form of diabetes may have insulin levels that appear normal
or elevated, the higher blood glucose levels in these diabetic
patients would be expected to result in even higher insulin
values had their ß-cell function been normal. Thus,
insulin secretion is defective in these patients and insufficient
to compensate for insulin resistance. Insulin resistance may
improve with weight reduction and/or pharmacological treatment
of hyperglycemia but is seldom restored to normal The risk
of developing this form of diabetes increases with age, obesity,
and lack of physical activity. It occurs more frequently in
women with prior GDM and in individuals with hypertension
or dyslipidemia, and its frequency varies in different racial/ethnic
subgroups. It is often associated with a strong genetic predisposition,
more so than is the autoimmune form of type 1 diabetes. However,
the genetics of this form of diabetes are complex and not
clearly defined.
Other
specific types of diabetes
Genetic
defects of the ß-cell.
Several
forms of diabetes are associated with monogenetic defects
in ß-cell function. These forms of diabetes are frequently
characterized by onset of hyperglycemia at an early age (generally
before age 25 years). They are referred to as maturity-onset
diabetes of the young (MODY) and are characterized by impaired
insulin secretion with minimal or no defects in insulin action.
They are inherited in an autosomal dominant pattern. Abnormalities
at six genetic loci on different chromosomes have been identified
to date. The most common form is associated with mutations
on chromosome 12 in a hepatic transcription factor referred
to as hepatocyte nuclear factor (HNF)-1 . A second form is
associated with mutations in the glucokinase gene on chromosome
7p and results in a defective glucokinase molecule. Glucokinase
converts glucose to glucose-6-phosphate, the metabolism of
which, in turn, stimulates insulin secretion by the ß-cell.
Thus, glucokinase serves as the "glucose sensor"
for the ß-cell. Because of defects in the glucokinase
gene, increased plasma levels of glucose are necessary to
elicit normal levels of insulin secretion. The less common
forms result from mutations in other transcription factors,
including HNF-4 , HNF-1ß, insulin promoter factor (IPF)-1,
and NeuroD1.
Point mutations in mitochondrial DNA have been found to be
associated with diabetes mellitus and deafness The most common
mutation occurs at position 3243 in the tRNA leucine gene,
leading to an A-to-G transition. An identical lesion occurs
in the MELAS syndrome (mitochondrial myopathy, encephalopathy,
lactic acidosis, and stroke-like syndrome); however, diabetes
is not part of this syndrome, suggesting different phenotypic
expressions of this genetic lesion.
Genetic
abnormalities that result in the inability to convert proinsulin
to insulin have been identified in a few families, and such
traits are inherited in an autosomal dominant pattern. The
resultant glucose intolerance is mild. Similarly, the production
of mutant insulin molecules with resultant impaired receptor
binding has also been identified in a few families and is
associated with an autosomal inheritance and only mildly impaired
or even normal glucose metabolism.
Genetic
defects in insulin action.
There
are unusual causes of diabetes that result from genetically
determined abnormalities of insulin action. The metabolic
abnormalities associated with mutations of the insulin receptor
may range from hyperinsulinemia and modest hyperglycemia to
severe diabetes. Some individuals with these mutations may
have acanthosis nigricans. Women may be virilized and have
enlarged, cystic ovaries. In the past, this syndrome was termed
type A insulin resistance. Leprechaunism and the Rabson-Mendenhall
syndrome are two pediatric syndromes that have mutations in
the insulin receptor gene with subsequent alterations in insulin
receptor function and extreme insulin resistance. The former
has characteristic facial features and is usually fatal in
infancy, while the latter is associated with abnormalities
of teeth and nails and pineal gland hyperplasia.
Alterations
in the structure and function of the insulin receptor cannot
be demonstrated in patients with insulin-resistant lipoatrophic
diabetes. Therefore, it is assumed that the lesion(s) must
reside in the postreceptor signal transduction pathways.
Diseases
of the exocrine pancreas
Any
process that diffusely injures the pancreas can cause diabetes.
Acquired processes include pancreatitis, trauma, infection,
pancreatectomy, and pancreatic carcinoma. With the exception
of that caused by cancer, damage to the pancreas must be extensive
for diabetes to occur; adrenocarcinomas that involve only
a small portion of the pancreas have been associated with
diabetes. This implies a mechanism other than simple reduction
in ß-cell mass. If extensive enough, cystic fibrosis
and hemochromatosis will also damage ß-cells and impair
insulin secretion. Fibrocalculous pancreatopathy may be accompanied
by abdominal pain radiating to the back and pancreatic calcifications
identified on X-ray examination. Pancreatic fibrosis and calcium
stones in the exocrine ducts have been found at autopsy.
Endocrinopathies
Several
hormones (e.g., growth hormone, cortisol, glucagon, epinephrine)
antagonize insulin action. Excess amounts of these hormones
(e.g., acromegaly, Cushings syndrome, glucagonoma, pheochromocytoma,
respectively) can cause diabetes. This generally occurs in
individuals with preexisting defects in insulin secretion,
and hyperglycemia typically resolves when the hormone excess
is resolved.
Somatostatinoma-
and aldosteronoma-induced hypokalemia can cause diabetes,
at least in part, by inhibiting insulin secretion. Hyperglycemia
generally resolves after successful removal of the tumor.
Drug-
or chemical-induced diabetes
Many
drugs can impair insulin secretion. These drugs may not cause
diabetes by themselves, but they may precipitate diabetes
in individuals with insulin resistance. In such cases, the
classification is unclear because the sequence or relative
importance of ß-cell dysfunction and insulin resistance
is unknown. Certain toxins such as Vacor (a rat poison) and
intravenous pentamidine can permanently destroy pancreatic
ß-cells. Such drug reactions fortunately are rare. There
are also many drugs and hormones that can impair insulin action.
Examples include nicotinic acid and glucocorticoids. Patients
receiving -interferon have been reported to develop diabetes
associated with islet cell antibodies and, in certain instances,
severe insulin deficiency. The list shown in Table 1 is not
all-inclusive, but reflects the more commonly recognized drug-,
hormone-, or toxin-induced forms of diabetes.
Table
1 Etiologic classification of diabetes mellitus
I.
Type 1 diabetes (ß-cell destruction, usually leading
to absolute insulin deficiency)
A. Immune mediated
B. Idiopathic
II. Type 2 diabetes (may range from predominantly insulin
resistance with relative insulin deficiency to a predominantly
secretory defect
with insulin resistance)
III. Other specific types
A. Genetic defects of ß-cell
function
1. Chromosome
12, HNF-1 (MODY3)
2. Chromosome
7, glucokinase (MODY2)
3. Chromosome
20, HNF-4 (MODY1)
4. Chromosome
13, insulin promoter factor-1 (IPF-1; MODY4)
5. Chromosome
17, HNF-1ß (MODY5)
6. Chromosome
2, NeuroD1 (MODY6)
7. Mitochondrial
DNA
8. Others
B. Genetic defects in insulin action
1. Type A insulin resistance
2. Leprechaunism
3. Rabson-Mendenhall syndrome
4. Lipoatrophic diabetes
5. Others
C. Diseases of the exocrine pancreas
1. Pancreatitis
2. Trauma/pancreatectomy
3. Neoplasia
4. Cystic fibrosis
5. Hemochromatosis
6. Fibrocalculous pancreatopathy
7. Others
D. Endocrinopathies
1. Acromegaly
2. Cushings syndrome
3. Glucagonoma
4. Pheochromocytoma
5. Hyperthyroidism
6. Somatostatinoma
7. Aldosteronoma
8. Others
E. Drug- or chemical-induced
1. Vacor
2. Pentamidine
3. Nicotinic acid
4. Glucocorticoids
5. Thyroid hormone
6. Diazoxide
7. ß-adrenergic agonists
8. Thiazides
9. Dilantin
10. Interferon
11. Others
F. Infections
1. Congenital rubella
2. Cytomegalovirus
3. Others
G. Uncommon forms of immune-mediated diabetes
1. "Stiff-man" syndrome
2. Antiinsulin receptor antibodies
3. Others
H. Other genetic syndromes sometimes associated with diabetes
1. Downs syndrome
2. Klinefelters syndrome
3. Turners syndrome
4. Wolframs syndrome
5. Friedreichs ataxia
6. Huntingtons chorea
7. Laurence-Moon-Biedl syndrome
8. Myotonic dystrophy
9. Porphyria
10. Prader-Willi syndrome
11. Others
IV. Gestational diabetes mellitus (GDM)
Patients
with any form of diabetes may require insulin treatment at
some stage of their disease. Such use of insulin does not,
of itself, classify the patient.
Infections
Certain
viruses have been associated with ß-cell destruction.
Diabetes occurs in patients with congenital rubella, although
most of these patients have HLA and immune markers characteristic
of type 1 diabetes. In addition, coxsackievirus B, cytomegalovirus,
adenovirus, and mumps have been implicated in inducing certain
cases of the disease.
Uncommon
forms of immune-mediated diabetes
In
this category, there are two known conditions, and others
are likely to occur. The stiff-man syndrome is an autoimmune
disorder of the central nervous system characterized by stiffness
of the axial muscles with painful spasms. Patients usually
have high titers of the GAD autoantibodies, and approximately
one-third will develop diabetes.
Antiinsulin
receptor antibodies can cause diabetes by binding to the insulin
receptor, thereby blocking the binding of insulin to its receptor
in target tissues. However, in some cases, these antibodies
can act as an insulin agonist after binding to the receptor
and can thereby cause hypoglycemia. Antiinsulin receptor
antibodies are occasionally found in patients with systemic
lupus erythematosus and other autoimmune diseases. As in other
states of extreme insulin resistance, patients with antiinsulin
receptor antibodies often have acanthosis nigricans. In the
past, this syndrome was termed type B insulin resistance.
Other
genetic syndromes sometimes associated with diabetes
Many
genetic syndromes are accompanied by an increased incidence
of diabetes mellitus. These include the chromosomal abnormalities
of Downs syndrome, Klinefelters syndrome, and
Turners syndrome. Wolframs syndrome is an autosomal
recessive disorder characterized by insulin-deficient diabetes
and the absence of ß-cells at autopsy. Additional manifestations
include diabetes insipidus, hypogonadism, optic atrophy, and
neural deafness. Other syndromes are listed in Table 1.
Gestational
diabetes mellitus (GDM)
GDM
is defined as any degree of glucose intolerance with onset
or first recognition during pregnancy. The definition applies
regardless of whether insulin or only diet modification is
used for treatment or whether the condition persists after
pregnancy. It does not exclude the possibility that unrecognized
glucose intolerance may have antedated or begun concomitantly
with the pregnancy. GDM complicates 4% of all pregnancies
in the U.S., resulting in 135,000 cases annually. The prevalence
may range from 1 to 14% of pregnancies, depending on the population
studied. GDM represents nearly 90% of all pregnancies complicated
by diabetes.
Deterioration
of glucose tolerance occurs normally during pregnancy, particularly
in the 3rd trimester.
Impaired
glucose tolerance (IGT) and impaired fasting glucose (IFG)
The
Expert Committee recognized an intermediate group of subjects
whose glucose levels, although not meeting criteria for diabetes,
are nevertheless too high to be considered normal. This group
is defined as having fasting plasma glucose (FPG) levels 100
mg/dl (5.6 mmol/l) but <126 mg/dl (7.0 mmol/l) or 2-h values
in the oral glucose tolerance test (OGTT) of 140 mg/dl (7.8
mmol/l) but <200 mg/dl (11.1 mmol/l). Thus, the categories
of FPG values are as follows:
- FPG
<100 mg/dl (5.6 mmol/l) = normal fasting glucose;
- FPG
100125 mg/dl (5.66.9 mmol/l) = IFG (impaired
fasting glucose);
- FPG
126 mg/dl (7.0 mmol/l) = provisional diagnosis of diabetes
(the diagnosis must be confirmed, as described below).
The
corresponding categories when the OGTT is used are the following:
- 2-h
postload glucose <140 mg/dl (7.8 mmol/l) = normal glucose
tolerance;
- 2-h
postload glucose 140199 mg/dl (7.811.1 mmol/l)
= IGT (impaired glucose tolerance);
- 2-h
postload glucose 200 mg/dl (11.1 mmol/l) = provisional diagnosis
of diabetes (the diagnosis must be confirmed, as described
below).
Patients
with IFG and/or IGT are now referred to as having "pre-diabetes"
indicating the relatively high risk for development of diabetes
in these patients. In the absence of pregnancy, IFG and IGT
are not clinical entities in their own right but rather risk
factors for future diabetes as well as cardiovascular disease.
They can be observed as intermediate stages in any of the
disease processes listed in Table
1. IFG and IGT are associated with the metabolic syndrome,
which includes obesity (especially abdominal or visceral obesity),
dyslipidemia of the high-triglyceride and/or low-HDL type,
and hypertension. It is worth mentioning that medical nutrition
therapy aimed at producing 510% loss of body weight,
exercise, and certain pharmacological agents have been variably
demonstrated to prevent or delay the development of diabetes
in people with IGT; the potential impact of such interventions
to reduce cardiovascular risk has not been examined to date.
Note
that many individuals with IGT are euglycemic in their daily
lives. Individuals with IFG or IGT may have normal or near
normal glycated hemoglobin levels. Individuals with IGT often
manifest hyperglycemia only when challenged with the oral
glucose load used in the standardized OGTT.
DIAGNOSTIC
CRITERIA FOR DIABETES MELLITUS
The criteria for the diagnosis of diabetes are shown in Table
2. Three ways to diagnose diabetes are possible, and each,
in the absence of unequivocal hyperglycemia, must be confirmed,
on a subsequent day, by any one of the three methods given
in Table
2. The use of the hemoglobin A1c (A1C) for the diagnosis
of diabetes is not recommended at this time.
Table
2 Criteria for the diagnosis of diabetes mellitus
1.
Symptoms of diabetes plus casual plasma glucose concentration
200 mg/dl (11.1 mmol/l). Casual is defined as any time of
day without regard to time since last meal. The classic symptoms
of diabetes include polyuria, polydipsia, and unexplained
weight loss.
OR
2.
FPG 126 mg/dl (7.0 mmol/l). Fasting is defined as no caloric
intake for at least 8 h.
OR
3.
2-h postload glucose 200 mg/dl (11.1 mmol/l) during an OGTT.
The test should be performed as described by WHO, using a
glucose load containing the equivalent of 75 g anhydrous glucose
dissolved in water.
In
the absence of unequivocal hyperglycemia, these criteria should
be confirmed by repeat testing on a different day. The third
measure (OGTT) is not recommended for routine clinical use.
Diagnosis of GDM
The
criteria for abnormal glucose tolerance in pregnancy are those
of Carpenter and Coustan. Recommendations from the American
Diabetes Associations Fourth International Workshop-Conference
on Gestational Diabetes Mellitus held in March 1997 support
the use of the Carpenter/Coustan diagnostic criteria as well
as the alternative use of a diagnostic 75-g 2-h OGTT. These
criteria are summarized below.
Testing
for gestational diabetes
Previous
recommendations included screening for GDM performed in all
pregnancies. However, there are certain factors that place
women at lower risk for the development of glucose intolerance
during pregnancy, and it is likely not cost-effective to screen
such patients. Pregnant women who fulfill all of these criteria
need not be screened for GDM.
This
low-risk group comprises women who
- are
<25 years of age
- are
a normal body weight
- have
no family history (i.e., first-degree relative) of diabetes
- have
no history of abnormal glucose metabolism
- have
no history of poor obstetric outcome
- are
not members of an ethnic/racial group with a high prevalence
of diabetes (e.g., Hispanic American, Native American, Asian
American, African American, Pacific Islander)
Risk
assessment for GDM should be undertaken at the first prenatal
visit. Women with clinical characteristics consistent with
a high risk of GDM (marked obesity, personal history of GDM,
glycosuria, or a strong family history of diabetes) should
undergo glucose testing (see below) as soon as feasible. If
they are found not to have GDM at that initial screening,
they should be retested between 24 and 28 weeks of gestation.
Women of average risk should have testing undertaken at 2428
weeks of gestation.
A
fasting plasma glucose level >126 mg/dl (7.0 mmol/l) or
a casual plasma glucose >200 mg/dl (11.1 mmol/l) meets
the threshold for the diagnosis of diabetes. In the absence
of unequivocal hyperglycemia, the diagnosis must be confirmed
on a subsequent day. Confirmation of the diagnosis precludes
the need for any glucose challenge. In the absence of this
degree of hyperglycemia, evaluation for GDM in women with
average or high-risk characteristics should follow one of
two approaches.
One-step
approach
Perform
a diagnostic OGTT without prior plasma or serum glucose screening.
The one-step approach may be cost-effective in high-risk patients
or populations (e.g., some Native-American groups).
Two-step
approach
Perform
an initial screening by measuring the plasma or serum glucose
concentration 1 h after a 50-g oral glucose load (glucose
challenge test [GCT]) and perform a diagnostic OGTT on that
subset of women exceeding the glucose threshold value on the
GCT. When the two-step approach is used, a glucose threshold
value >140 mg/dl (7.8 mmol/l) identifies 80% of women with
GDM, and the yield is further increased to 90% by using a
cutoff of >130 mg/dl (7.2 mmol/l).
With
either approach, the diagnosis of GDM is based on an OGTT.
Diagnostic criteria for the 100-g OGTT are derived from the
original work of OSullivan and Mahan (4) modified by
Carpenter and Coustan (3) and are shown in the top of Table
3. Alternatively, the diagnosis can be made using a 75-g glucose
load and the glucose threshold values listed for fasting,
1 h, and 2 h (Table 2, bottom); however, this test is not
as well validated as the 100-g OGTT.
Table
3 Diagnosis of GDM with a 100-g or 75-g glucose load
| |
|
mg/dl
|
mmol/l
|
| |
100-g
glucose load |
|
|
| |
Fasting |
95
|
5.3
|
| |
1-h |
180
|
10.0
|
| |
2-h
|
155
|
8.6
|
| |
3-h |
140
|
7.8
|
| |
75-g
glucose load |
|
|
| |
Fasting |
95
|
5.3
|
| |
1-h |
180
|
10.0
|
| |
2-h |
155
|
8.6
|
|
Two
or more of the venous plasma concentrations must be met or
exceeded for a positive diagnosis. The test should be done
in the morning after an overnight fast of between 8 and 14
h and after at least 3 days of unrestricted diet ( 150 g carbohydrate
per day) and unlimited physical activity. The subject should
remain seated and should not smoke throughout the test.
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Diabetes
Care in the School and Day Care Setting
|
INTRODUCTION
Diabetes is one of the most common chronic diseases of childhood.
There are about 176,000 individuals <20 years of age with
diabetes in the U.S. The majority of these young people attend
school and/or some type of day care and need knowledgeable
staff to provide a safe school environment. Both parents and
the health care team should work together to provide school
systems and day care providers with the information necessary
to allow children with diabetes to participate fully and safely
in the school experience.
DIABETES
AND THE LAW
Federal laws that protect children with diabetes include Section
504 of the Rehabilitation Act of 1973, the Individuals with
Disabilities Education Act of 1991 (originally the Education
for All Handicapped Children Act of 1975), and the Americans
with Disabilities Act. Under these laws, diabetes has been
considered to be a disability, and it is illegal for schools
and/or day care centers to discriminate against children with
disabilities. In addition, any school that receives federal
funding or any facility considered open to the public must
reasonably accommodate the special needs of children with
diabetes. Indeed, federal law requires an individualized assessment
of any child with diabetes. The required accommodations should
be provided within the childs usual school setting with
as little disruption to the schools and the childs
routine as possible and allowing the child full participation
in all school activities.
Despite
these protections, children in the school and day care setting
still face discrimination. For example, some day care centers
may refuse admission to children with diabetes, and children
in the classroom may not be provided the assistance necessary
to monitor blood glucose and may be prohibited from eating
needed snacks. The American Diabetes Association works to
ensure the safe and fair treatment of children with diabetes
in the school and day care setting (www.diabetes.org/schooldiscrimination).
Diabetes
care in schools
Appropriate
diabetes care in the school and day care setting is necessary
for the childs immediate safety, long-term well being,
and optimal academic performance. The Diabetes Control and
Complications Trial showed a significant link between blood
glucose control and the later development of diabetes complications,
with improved glycemic control decreasing the risk of these
complications. To achieve glycemic control, a child must monitor
blood glucose frequently, follow a meal plan, and take medications.
Insulin is usually taken in multiple daily injections or through
an infusion pump. Crucial to achieving glycemic control is
an understanding of the effects of physical activity, nutrition
therapy, and insulin on blood glucose levels.
To
facilitate the appropriate care of the student with diabetes,
school and day care personnel must have an understanding of
diabetes and must be trained in its management and in the
treatment of diabetes emergencies. Knowledgeable trained personnel
are essential if the student is to avoid the immediate health
risks of low blood glucose and to achieve the metabolic control
required to decrease risks for later development of diabetes
complications. Studies have shown that the majority of school
personnel have an inadequate understanding of diabetes and
that parents of children with diabetes lack confidence in
their teachers ability to manage diabetes effectively.
Consequently, diabetes education must be targeted toward day
care providers, teachers, and other school personnel who interact
with the child, including school administrators, school coaches,
school nurses, health aides, bus drivers, secretaries, etc.
Current recommendations and up-to-date resources regarding
appropriate care for children with diabetes in the school
are universally available to all school personnel.
The
purpose of this position statement is to provide recommendations
for the management of children with diabetes in the school
and day care setting.
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