Diabetes Care
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Diabetes Care 30:S4-S41, 2007
DOI: 10.2337/dc07-S004
© 2007 by the American Diabetes Association
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Position Statements
Position Statement

Standards of Medical Care in Diabetes—2007

American Diabetes Association

Abbreviations: ABI, ankle-brachial index • AMI, acute myocardial 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 • CMS, Centers for Medicare and Medicaid Services • CSII, continuous subcutaneous insulin infusion • 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 • NDEP, National Diabetes Education Program • 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 • UKPDS, U.K. Prospective Diabetes Study


    INTRODUCTION
 TOP
 INTRODUCTION
 I. CLASSIFICATION AND DIAGNOSIS
 II. SCREENING FOR DIABETES
 III. DETECTION AND DIAGNOSIS...
 IV. PREVENTION/DELAY OF TYPE...
 V. DIABETES CARE
 D. MNT (42)
 E. DSME
 F. Physical activity
 G. Psychosocial assessment and...
 H. Referral for diabetes...
 I. Intercurrent illness
 J. Hypoglycemia
 K. Immunization
 VI. PREVENTION AND MANAGEMENT...
 B. Nephropathy screening and...
 C. Retinopathy screening and...
 D. Neuropathy screening and...
 E. Foot care
 VII. DIABETES CARE IN...
 B. Preconception care
 C. Older individuals
 VIII. DIABETES CARE IN...
 B. Diabetes care in...
 IX. HYPOGLYCEMIA AND...
 X. THIRD-PARTY REIMBURSEMENT FOR...
 XI. STRATEGIES FOR IMPROVING...
 References
 
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. For more detailed information, refer to refs. 13.

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.


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Table 1— ADA evidence grading system for clinical practice recommendations

 

    I. CLASSIFICATION AND DIAGNOSIS
 TOP
 INTRODUCTION
 I. CLASSIFICATION AND DIAGNOSIS
 II. SCREENING FOR DIABETES
 III. DETECTION AND DIAGNOSIS...
 IV. PREVENTION/DELAY OF TYPE...
 V. DIABETES CARE
 D. MNT (42)
 E. DSME
 F. Physical activity
 G. Psychosocial assessment and...
 H. Referral for diabetes...
 I. Intercurrent illness
 J. Hypoglycemia
 K. Immunization
 VI. PREVENTION AND MANAGEMENT...
 B. Nephropathy screening and...
 C. Retinopathy screening and...
 D. Neuropathy screening and...
 E. Foot care
 VII. DIABETES CARE IN...
 B. Preconception care
 C. Older individuals
 VIII. DIABETES CARE IN...
 B. Diabetes care in...
 IX. HYPOGLYCEMIA AND...
 X. THIRD-PARTY REIMBURSEMENT FOR...
 XI. STRATEGIES FOR IMPROVING...
 References
 
A. Classification
In 1997, ADA issued new diagnostic and classification criteria (4); in 2003, modifications were made regarding the diagnosis of impaired fasting glucose (IFG) (5). 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)

Some patients cannot be clearly classified as type 1 or type 2 diabetes. Clinical presentation and disease progression vary considerably in both types of diabetes. Occasionally, patients who otherwise have type 2 diabetes may present with ketoacidosis. Similarly, patients with type 1 may have a late onset and slow (but relentless) progression of disease despite having features of autoimmune disease. Such difficulties in diagnosis may occur in children, adolescents, and adults. The true diagnosis may become more obvious over time.

B. Diagnosis
Recommendations

  • The FPG is the preferred test to diagnose diabetes in children and nonpregnant adults. (E)
  • 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.


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Table 2— Criteria for the diagnosis of diabetes

 
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 an 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
 TOP
 INTRODUCTION
 I. CLASSIFICATION AND DIAGNOSIS
 II. SCREENING FOR DIABETES
 III. DETECTION AND DIAGNOSIS...
 IV. PREVENTION/DELAY OF TYPE...
 V. DIABETES CARE
 D. MNT (42)
 E. DSME
 F. Physical activity
 G. Psychosocial assessment and...
 H. Referral for diabetes...
 I. Intercurrent illness
 J. Hypoglycemia
 K. Immunization
 VI. PREVENTION AND MANAGEMENT...
 B. Nephropathy screening and...
 C. Retinopathy screening and...
 D. Neuropathy screening and...
 E. Foot care
 VII. DIABETES CARE IN...
 B. Preconception care
 C. Older individuals
 VIII. DIABETES CARE IN...
 B. Diabetes care in...
 IX. HYPOGLYCEMIA AND...
 X. THIRD-PARTY REIMBURSEMENT FOR...
 XI. STRATEGIES FOR IMPROVING...
 References
 
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)


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Table 3— Criteria for testing for diabetes in asymptomatic adult individuals

 
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: 1) cutoff values for some of the immune marker assays have not been completely established in clinical settings; 2) there is no consensus as to what action should be taken when a positive autoantibody test result is obtained; and 3) 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 (6).

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 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 (7). 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 (810), 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 (4,5). 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 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 (11) (Table 4).


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Table 4— Testing for type 2 diabetes in children

 
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 (12,13).

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
 TOP
 INTRODUCTION
 I. CLASSIFICATION AND DIAGNOSIS
 II. SCREENING FOR DIABETES
 III. DETECTION AND DIAGNOSIS...
 IV. PREVENTION/DELAY OF TYPE...
 V. DIABETES CARE
 D. MNT (42)
 E. DSME
 F. Physical activity
 G. Psychosocial assessment and...
 H. Referral for diabetes...
 I. Intercurrent illness
 J. Hypoglycemia
 K. Immunization
 VI. PREVENTION AND MANAGEMENT...
 B. Nephropathy screening and...
 C. Retinopathy screening and...
 D. Neuropathy screening and...
 E. Foot care
 VII. DIABETES CARE IN...
 B. Preconception care
 C. Older individuals
 VIII. DIABETES CARE IN...
 B. Diabetes care in...
 IX. HYPOGLYCEMIA AND...
 X. THIRD-PARTY REIMBURSEMENT FOR...
 XI. STRATEGIES FOR IMPROVING...
 References
 
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 6–12 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 (e.g., those with marked obesity, personal history of GDM or delivery of a previous large-for-gestation-age infant, glycosuria, polycystic ovary syndrome, or a strong family history of diabetes) should undergo glucose testing as soon as possible (14). 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 as soon as possible 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 8–14 h. The diagnosis can be made using a 2-h, 75-g glucose tolerance test, but that test is not as well validated for detection of at-risk infants or mothers as the 3-h, 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 diabetes
  • No known diabetes in first-degree relatives
  • No history of abnormal glucose tolerance
  • No history of poor obstetric outcome

Because women with a history of GDM have an increased subsequent risk for diabetes, they should be screened for diabetes 6–12 weeks postpartum and should be followed up with subsequent screening for the development of diabetes or pre-diabetes. For information on the National Diabetes Education Program (NDEP) campaign to prevent type 2 diabetes in women with GDM, go to www.ndep.nih.gov/diabetes/pubs/NeverTooEarly_Tipsheet.pdf.


    IV. PREVENTION/DELAY OF TYPE 2 DIABETES
 TOP
 INTRODUCTION
 I. CLASSIFICATION AND DIAGNOSIS
 II. SCREENING FOR DIABETES
 III. DETECTION AND DIAGNOSIS...
 IV. PREVENTION/DELAY OF TYPE...
 V. DIABETES CARE
 D. MNT (42)
 E. DSME
 F. Physical activity
 G. Psychosocial assessment and...
 H. Referral for diabetes...
 I. Intercurrent illness
 J. Hypoglycemia
 K. Immunization
 VI. PREVENTION AND MANAGEMENT...
 B. Nephropathy screening and...
 C. Retinopathy screening and...
 D. Neuropathy screening and...
 E. Foot care
 VII. DIABETES CARE IN...
 B. Preconception care
 C. Older individuals
 VIII. DIABETES CARE IN...
 B. Diabetes care in...
 IX. HYPOGLYCEMIA AND...
 X. THIRD-PARTY REIMBURSEMENT FOR...
 XI. STRATEGIES FOR IMPROVING...
 References
 
Recommendations

  • Individuals at high risk for developing diabetes need to become aware of the many 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) (Reimbursement for such counseling is encouraged.)
  • Patients with IFG should be given counseling on weight loss as well as instruction for increasing physical activity. (E) (Reimbursement for such counseling is encouraged.)
  • Follow-up counseling appears to be important for success. (B)
  • Monitoring for the development of diabetes in those with pre-diabetes should be performed every 1–2 years. (E)
  • Close attention should be given to, and appropriate treatment given for, other CVD risk factors (e.g., tobacco use, hypertension, dyslipidemia). (A)
  • Because of possible side effects and cost, there is insufficient evidence to support the use of drug therapy. (E)

Many studies have shown that individuals at high risk for developing diabetes (those with IFG, IGT, or both) can be given a wide variety of interventions that significantly delay, and sometimes prevent, the onset of diabetes (810,1518). An intensive lifestyle modification program has been shown to be very effective (~58% reduction after 3 years). Use of the pharmacologic agents metformin, acarbose, orlistat, and rosiglitazone has also been shown to decrease incident diabetes to various degrees. Of note, however, each of these drugs may cause side effects of varying severity in a small number of individuals.

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 DPP lifestyle group, 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 120–174 lb (54–78 kg) at baseline were instructed to follow a 1,200 kcal/day diet (33 g fat), those 175–219 lb (79–99 kg) were instructed to follow a 1,500 kcal/day diet (42 g fat), those 220–249 lb (100–113 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). 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 (8). 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 (9); "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.

Lifestyle or medication?
Many factors must be considered when undertaking the effort to modify the course of glucose intolerance. Lifestyle modification may have other beneficial effects (e.g., reduced CVD), but is often very difficult to sustain, and its cost-effectiveness is questionable if the regimen is similar to what was employed in clinical trials. Even so, lifestyle intervention still may be cost-effective compared with some pharmacologic treatments. Drug therapy can be very costly (except for metformin, which is a generic drug), and side effects can range from mild/moderate discomfort to serious cardiovascular events. Finally, whether diabetes prevention efforts can, over the long term, influence the development of micro- or macrovascular events is unknown. It is possible that at least microvascular complications will be delayed or diminished, since they are more closely related to hyperglycemia.

In light of the above, health care professionals should first actively counsel patients to maintain normal weight and exercise regularly (even before glucose intolerance occurs). Because of potential side effects and cost, 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 how to better facilitate effective and efficient programs for the primary prevention of type 2 diabetes.

An ADA consensus statement offering more comprehensive guidance on diabetes prevention will be published in 2007.


    V. DIABETES CARE
 TOP
 INTRODUCTION
 I. CLASSIFICATION AND DIAGNOSIS
 II. SCREENING FOR DIABETES
 III. DETECTION AND DIAGNOSIS...
 IV. PREVENTION/DELAY OF TYPE...
 V. DIABETES CARE
 D. MNT (42)
 E. DSME
 F. Physical activity
 G. Psychosocial assessment and...
 H. Referral for diabetes...
 I. Intercurrent illness
 J. Hypoglycemia
 K. Immunization
 VI. PREVENTION AND MANAGEMENT...
 B. Nephropathy screening and...
 C. Retinopathy screening and...
 D. Neuropathy screening and...
 E. Foot care
 VII. DIABETES CARE IN...
 B. Preconception care
 C. Older individuals
 VIII. DIABETES CARE IN...
 B. Diabetes care in...
 IX. HYPOGLYCEMIA AND...
 X. THIRD-PARTY REIMBURSEMENT FOR...
 XI. STRATEGIES FOR IMPROVING...
 References
 
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 patient’s 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.


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Table 5— Components of the comprehensive diabetes evaluation

 
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, physician’s 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 patient’s 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 patient’s technique and ability to use data to adjust therapy. (E)

The ADA’s consensus statements on SMBG provide a comprehensive review of the subject (19,20). 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. A recent meta-analysis of SMBG in non–insulin-treated patients with type 2 diabetes concluded that some regimen of monitoring was associated with a reduction in A1C of ~0.4%. However, many of the studies in this analysis also included patient education with diet and exercise counseling and, in some cases, pharmacologic intervention, making it very difficult to assess the contribution of SMBG alone to improved control (21). 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 (22), it is important for health care providers to evaluate each patient’s 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 patient’s 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 patient’s average glycemia over the preceding 2–3 months (22) 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 2–3 months, measurement approximately every 3 months is required to determine whether a patient’s 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.


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Table 6— Summary of recommendations for adults with diabetes

 
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 patient’s clinical situation (22). 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 (23,24).

Glycemic control is best judged by the combination of the results of the patient’s SMBG testing (as performed) and the current A1C result. The A1C should be used not only to assess the patient’s control over the preceding 2–3 months, but also as a check on the accuracy of the meter (or the patient’s 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) (25).


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Table 7— Correlation between A1C level and mean plasma glucose levels on multiple testing over 2–3 months (25)

 
2. Glycemic goals

Recommendations

  • Lowering A1C has been associated with a reduction of microvascular and neuropathic complications of diabetes (A) and possibly macrovascular disease (B).
  • 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 achieve 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 (26). Prospective, randomized, clinical trials in type 1 diabetes such as the DCCT (27,28) have shown that improved glycemic control is associated with sustained decreased rates of microvascular (retinopathy and nephropathy), macrovascular, and neuropathic complications (2831).

In type 2 diabetes, the U.K. Prospective Diabetes Study (UKPDS) demonstrated significant reductions in microvascular and neuropathic complications with intensive therapy (3234). The potential of intensive glycemic control to reduce CVD in type 2 diabetes is supported by epidemiological studies (3234) and a recent meta-analysis (35), but this potential benefit on CVD events has not been demonstrated in a randomized clinical trial.

In each of these large randomized prospective clinical 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 (31,34).

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]) of 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 are not meeting A1C targets, monitoring PPG 1–2 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 (36).

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 (37). For further information on GDM, refer to the ADA position statement (14). For information on glycemic control during pregnancy in women with preexisting diabetes, refer to ref. 38.

3. Approach to treatment.

A consensus statement from the ADA and the European Association for the Study of Diabetes on the approach to management of hyperglycemia in individuals with type 2 diabetes has recently been published (39). Early intervention with metformin in combination with lifestyle changes (MNT and exercise) with continuing, timely augmentation therapy with additional agents (including early initiation of insulin therapy) as a means of achieving and maintaining recommended levels of glycemic control (i.e., A1C <7% for most patients) are highlights of this approach. See Fig. 1 for metabolic management of type 2 diabetes.


Figure 1
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Figure 1— Algorithm for the metabolic management of type 2 diabetes. Reinforce lifestyle intervention at every visit. *Check A1C every 3 months until <7% and then at least every 6 months. +Although three oral agents can be used, initiation and intensification of insulin therapy is preferred based on effectiveness and expense. #See Fig. 1 in ref. 39 for initiation and adjustment of insulin.

 
Early initiation of insulin would be a safer approach for individuals presenting with weight loss, more severe symptoms, and glucose values >250–300 mg/dl.

Insulin therapy, consisting of intermediate- or long-acting basal insulin in combination with premeal rapid- or short-acting insulin is recommended for all patients with type 1 diabetes. An algorithm for adjusting premeal insulin doses to correct for blood glucose values outside of target ranges is appropriate for most patients with type 1 diabetes and insulin-treated type 2 diabetes. There are excellent reviews available that guide the initiation and management of insulin therapy to achieve desired glycemic goals (40,41).


    D. MNT (42)
 TOP
 INTRODUCTION
 I. CLASSIFICATION AND DIAGNOSIS
 II. SCREENING FOR DIABETES
 III. DETECTION AND DIAGNOSIS...
 IV. PREVENTION/DELAY OF TYPE...
 V. DIABETES CARE
 D. MNT (42)
 E. DSME
 F. Physical activity
 G. Psychosocial assessment and...
 H. Referral for diabetes...
 I. Intercurrent illness
 J. Hypoglycemia
 K. Immunization
 VI. PREVENTION AND MANAGEMENT...
 B. Nephropathy screening and...
 C. Retinopathy screening and...
 D. Neuropathy screening and...
 E. Foot care
 VII. DIABETES CARE IN...
 B. Preconception care
 C. Older individuals
 VIII. DIABETES CARE IN...
 B. Diabetes care in...
 IX. HYPOGLYCEMIA AND...
 X. THIRD-PARTY REIMBURSEMENT FOR...
 XI. STRATEGIES FOR IMPROVING...
 References
 
Recommendations
Diabetes and obesity management

  • Individuals who have pre-diabetes or 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)
  • MNT should be covered by insurance and other payors. (E)
  • In overweight and obese insulin-resistant individuals, modest weight loss has been shown to reduce insulin resistance. Thus, weight loss is recommended for all overweight or obese individuals who have or are at risk for diabetes. (A)
  • Structured programs that emphasize lifestyle changes, including education, reduced energy and fat (~30% of total energy) intake, regular physical activity, and regular participant contact, can produce long-term weight loss on the order of 5–7% of starting weight. Thus, lifestyle change should be the primary approach to weight loss. (A)
  • Physical activity and behavior modification are important components of weight loss programs and are most helpful in maintenance of weight loss. (B)

Fat intake

  • Saturated fat intake should be <7% of total calories. (A)
  • Intake of trans fat should be minimized. (E)

Carbohydrate intake

  • Monitoring carbohydrate, whether by carbohydrate counting, exchanges, or experience-based estimation, remains a key strategy in achieving glycemic control. (A)
  • For individuals with diabetes, the use of the glycemic index and glycemic load may provide a modest additional benefit for glycemic control over that observed when total carbohydrate is considered alone. (B)
  • There is not sufficient evidence to recommend use of glycemic index or glycemic load for prevention of diabetes, although foods high in fiber are encouraged. (E)
  • Low-carbohydrate diets (restricting total carbohydrate to <130 g/day) are not recommended in the treatment of overweight/obesity. The long-term effects of these diets are unknown, and although such diets produce short-term weight loss, maintenance of weight loss is similar to that from low-fat diets and the impact on CVD risk profile is uncertain. (B)

Other nutrition recommendations

  • Sugar alcohols and 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). (E)
  • Routine supplementation with antioxidants, such as vitamins E and C and 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, ADA recognizes the importance of nutrition as an essential component of an overall healthy lifestyle. These recommendations are based on principles of good nutrition for the overall population from the 2005 Dietary Guidelines (43) and the recommended dietary allowances (RDAs) from the Institute of Medicine of the National Academies of Sciences (44). A review of the evidence regarding nutrition in preventing and controlling diabetes and its complications for the above nutrition recommendations and additional nutrition-related recommendations can be found elsewhere in this document. 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.

For those individuals seeking guidance regarding macronutrient distribution, the DRIs may be helpful. The DRI report recommends that to meet the body’s daily nutritional needs while minimizing risk for chronic diseases, adults (in general, not specifically those with diabetes) should consume 45–65% of total energy from carbohydrate, 20–35% from fat, and 10–35% from protein (44). The best mix of carbohydrate, protein, and fat appears to vary depending on individual circumstances.


    E. DSME
 TOP
 INTRODUCTION
 I. CLASSIFICATION AND DIAGNOSIS
 II. SCREENING FOR DIABETES
 III. DETECTION AND DIAGNOSIS...
 IV. PREVENTION/DELAY OF TYPE...
 V. DIABETES CARE
 D. MNT (42)
 E. DSME
 F. Physical activity
 G. Psychosocial assessment and...
 H. Referral for diabetes...
 I. Intercurrent illness
 J. Hypoglycemia
 K. Immunization
 VI. PREVENTION AND MANAGEMENT...
 B. Nephropathy screening and...
 C. Retinopathy screening and...
 D. Neuropathy screening and...
 E. Foot care
 VII. DIABETES CARE IN...
 B. Preconception care
 C. Older individuals
 VIII. DIABETES CARE IN...
 B. Diabetes care in...
 IX. HYPOGLYCEMIA AND...
 X. THIRD-PARTY REIMBURSEMENT FOR...
 XI. STRATEGIES FOR IMPROVING...
 References
 
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 (4551), 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 (46), improved self-care behavior (46), improved clinical outcomes such as lower A1C (47,48,50,51), lower self-reported weight (46), and improved quality of life (49). Better outcomes were reported for DSME that were longer and included follow-up support (46), that were tailored to individual needs and preferences (45), and that addressed psychosocial issues (45,46,50).

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 Centers for Medicare and Medicaid Services (CMS) (www.cms.hhs.gov/DiabetesSelfManagement).


    F. Physical activity
 TOP
 INTRODUCTION
 I. CLASSIFICATION AND DIAGNOSIS
 II. SCREENING FOR DIABETES
 III. DETECTION AND DIAGNOSIS...
 IV. PREVENTION/DELAY OF TYPE...
 V. DIABETES CARE
 D. MNT (42)
 E. DSME
 F. Physical activity
 G. Psychosocial assessment and...
 H. Referral for diabetes...
 I. Intercurrent illness
 J. Hypoglycemia
 K. Immunization
 VI. PREVENTION AND MANAGEMENT...
 B. Nephropathy screening and...
 C. Retinopathy screening and...
 D. Neuropathy screening and...
 E. Foot care
 VII. DIABETES CARE IN...
 B. Preconception care
 C. Older individuals
 VIII. DIABETES CARE IN...
 B. Diabetes care in...
 IX. HYPOGLYCEMIA AND...
 X. THIRD-PARTY REIMBURSEMENT FOR...
 XI. STRATEGIES FOR IMPROVING...
 References
 
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 (50–70% of maximum heart rate) and/or at least 90 min/week of vigorous aerobic exercise (>70% of maximum heart rate) is recommended. The physical activity should be distributed over at least 3 days/week and with no more than two 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 8–10 repetitions at a weight that cannot be lifted more than 8–10 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%. (E)

ADA technical reviews on exercise in patients with diabetes have summarized the value of exercise in the diabetes management plan (52,53). 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 (810).

Definitions
The following definitions are based on those outlined in Physical Activity and Health, the 1996 report of the Surgeon General (54). 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 component 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. (55) undertook a systematic review and meta-analysis on the effects of structured exercise interventions in clinical trials of duration ≥8 weeks on A1C 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 A1C was significantly lower in exercise than control groups. Metaregression confirmed that the beneficial effect of exercise on A1C 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. (56) later undertook a meta-analysis of the interrelationships among exercise intensity, exercise volume, change in cardiorespiratory fitness, and change in A1C. This meta-analysis provides support for higher-intensity aerobic exercise in people with type 2 diabetes as a means of improving A1C. 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 General’s report (54) 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 including resistance training in fitness programs for adults with type 2 diabetes (57). Resistance exercise improves insulin sensitivity to about the same extent as aerobic exercise (58). Two clinical trials published in 2002 provided strong evidence for the value of resistance training in type 2 diabetes (59,60).

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 patient’s 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 (61,62).

Exercise in the presence of nonoptimal glycemic control
Hyperglycemia.
When people with type 1 diabetes are deprived of insulin for 12–48 h and are ketotic, exercise can worsen hyperglycemia and ketosis (63). Vigorous activity should probably be avoided in the presence of ketosis. However, 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 is rare in diabetic individuals who are not treated with insulin or insulin secretagogues. Added carbohydrate should be ingested if preexercise glucose levels are <100 mg/dl (5.6 mmol/l) (64). Supplementary carbohydrate is generally not necessary for individuals treated only with diet, metformin, {alpha}-glucosidase inhibitors, and/or TZDs without insulin or a secretagogue (65).

Exercise in the presence of specific long-term complications of diabetes
Retinopathy.
In the presence of proliferative diabetic retinopathy (PDR) or severe non-PDR (NPDR), vigorous aerobic or resistance exercise may be contraindicated because of the risk of triggering vitreous hemorrhage or retinal detachment (66).

Peripheral neuropathy.
Decreased pain sensation in the extremities results 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 non–weight-bearing activities such as swimming, bicycling, or arm exercises (67,68).

Autonomic neuropathy.
Autonomic neuropathy can increase the risk of exercise-induced injury by decreasing cardiac responsiveness to exercise, postural hypotension