© 2006 by the American Diabetes Association © 2006 by the American Diabetes Association, Inc.
Standards of Medical Care in Diabetes2006American 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 UKPDS, U.K. Prospective Diabetes Study
I. CLASSIFICATION AND DIAGNOSIS, p. S4 A. Classification B. Diagnosis II. SCREENING FOR DIABETES, p. S5 III. DETECTION AND DIAGNOSIS OF GESTATIONAL DIABETES MELLITUS, p. S7 IV. PREVENTION/DELAY OF TYPE 2 DIABETES, p. S7 V. DIABETES CARE, p. S8 A. Initial evaluation B. Management C. Glycemic control 1. Assessment of glycemic control a. Self-monitoring of blood glucose b. A1C 2. Glycemic goals D. Medical nutrition therapy E. Diabetes self-management education F. Physical activity G. Psychosocial assessment and care H. Referral for diabetes management I. Intercurrent illness J. Hypoglycemia K. Immunization VI. PREVENTION AND MANAGEMENT OF DIABETES COMPLICATIONS, p. S17 A. Cardiovascular disease 1. Hypertension/blood pressure control 2. Dyslipidemia/lipid management 3. Antiplatelet agents 4. Smoking cessation 5. Coronary heart disease screening and treatment B. Nephropathy screening and treatment C. Retinopathy screening and treatment D. Neuropathy screening and treatment E. Foot care VII. DIABETES CARE IN SPECIFIC POPULATIONS, p. S26 A. Children and adolescents B. Preconception care C. Older individuals VIII. DIABETES CARE IN SPECIFIC SETTINGS, p. S29 A. Diabetes care in the hospital B. Diabetes care in the school and day care setting C. Diabetes care at diabetes camps D. Diabetes management in correctional institutions IX. HYPOGLYCEMIA AND EMPLOYMENT/LICENSURE, p. S34 X. THIRD-PARTY REIMBURSEMENT FOR DIABETES CARE, SELF-MANAGEMENT EDUCATION, AND SUPPLIES, p. S34 XI. STRATEGIES FOR IMPROVING DIABETES CARE, p. S34 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.
A. Classification In 1997, the 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:
B. Diagnosis
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.
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:
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.
Recommendations
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
Type 2 diabetes 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 (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 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 (11) (Table 4).
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
Recommendations
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 (14). An FPG
Diagnostic criteria for the 100-g OGTT are as follows: Low-risk status requires no glucose testing, but this category is limited to those women meeting all of the following characteristics:
Recommendations
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 (810,15,16). 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 (9), 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) (8), 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 In the Da Qing Study (10), 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 (15), 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 (16), participants with IGT were randomized in a double-blind fashion to receive either the
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 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 the DPP (8), the lifestyle group lost 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
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 ( There are also data to suggest that blockade of the renin-angiotensin system (17) may lower the risk of developing diabetes, but more studies are necessary before these drugs can be recommended for preventing diabetes.
Lifestyle or medication? 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.
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
a. Self-monitoring of blood glucose
The ADAs consensus statements on SMBG provide a comprehensive review of the subject (18,19). 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 (20), 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
By performing an A1C test, health providers can measure a patients average glycemia over the preceding 23 months (20) 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.
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 (20). 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 (21,22). 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) (23).
2. Glycemic goals Recommendations
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 (24). Prospective randomized clinical trials such as the DCCT (25) and the U.K. Prospective Diabetes Study (UKPDS) (26,27) have shown that improved glycemic control is associated with sustained decreased rates of retinopathy, nephropathy, and neuropathy (28). In these trials, treatment regimens that reduced average A1C to
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 ( 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 (32).
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
D. MNT
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 (35) and the 2004 ADA Statements regarding dietary carbohydrate (36) and weight management. (37). Goal of MNT that applies to individuals with pre-diabetes:
Goal of MNT that applies to all individuals with diabetes:
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 (37) In selected patients, drug therapy to achieve weight loss as an adjunct to lifestyle change may be appropriate (38). 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 (39). 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 (40). 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 (36) 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 (41), 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
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 (42). Based on studies in patients with varying stages of nephropathy (4244), it seems prudent to limit protein intake in those with diabetes to the RDA (0.8 g/kg), which would be
Dietary fat
Optimal macronutrient mix
Fiber
Reduced calorie sweetners 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
Chromium
Alcohol
Recommendations
DSME is an essential element of diabetes care (5258), 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
The national standards for DSME
Reimbursement for DSME
Recommendations
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