Practice Guidelines
ADA Releases Standards of Medical Care for Patients with Diabetes
Diabetes requires continuing medical care and patient self-management to prevent acute complications and to reduce the risk of long-term complications. Diabetes care is complex and requires that many issues-not only glycemic control-be managed. To address these issues, the American Diabetes Association (ADA) published a position statement containing evidence-based recommendations for diabetes care, treatment goals, and tools to evaluate the quality of care. The full statement, "Standards of Medical Care in Diabetes-2006," was published in the January 2006 supplement to Diabetes Care.
Screening
Type 2 diabetes usually is not diagnosed until complications develop, and approximately one third of all persons with diabetes may be undiagnosed. Screening to detect prediabetes should be considered in persons 45 years and older, particularly in persons with a body mass index (BMI) of at least 25 kg per m2. Screening also should be considered in persons who are younger than 45 years if they are overweight and have an additional risk factor (Table 1). Screening for prediabetes and diabetes should be performed in high-risk, asymptomatic children (Table 2) and adults. If test results are normal, repeat testing should be performed at three-year intervals in adults and at two-year intervals in children.
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TABLE 1 Criteria for Diabetes Testing in Asymptomatic Adults |
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| BMI = body mass index. Adapted with permission from American Diabetes Association. Standards of medical care in diabetes-2006. Diabetes Care 2006;29(suppl 1):S6. |
The two-hour oral glucose tolerance test (OGTT) identifies persons with impaired glucose tolerance levels, and thus, more persons who are at increased risk for developing diabetes and cardiovascular disease. Although the effectiveness of interventions for primary prevention of type 2 diabetes has been proven in persons with impaired glucose tolerance, data for persons with impaired fasting glucose levels (who do not also have impaired glucose tolerance) are not available. The fasting plasma glucose test is more convenient for patients, more reproducible, less costly, and easier to administer than the two-hour OGTT; therefore, the fasting plasma glucose test is recommended as the initial screening test for nonpregnant adults.
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TABLE 2 Testing for Type 2 Diabetes in Children |
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Adapted with permission from American Diabetes Association. Standards of medical care in diabetes-2006. Diabetes Care 2006;29(suppl 1):S6. |
Diabetes Care
Once a patient has been diagnosed with diabetes, a complete medical evaluation should be performed to classify the patient, detect any complications, formulate a management plan, and provide a basis for continuing care. The management plan should recognize that diabetes self-management education is an integral component of care. In developing the plan, the patient's age, school or work schedule and conditions, physical activity level, eating patterns, social situation and personality, cultural factors, and comorbid conditions should be considered.
glycemic control
Glycemic control is best judged by the combination of results of blood glucose self-monitoring and A1C testing. Blood glucose self-monitoring allows patients to evaluate their individual response to therapy and assess whether glycemic targets are being achieved. Patients taking multiple insulin injections should perform blood glucose self-monitoring at least three times daily to monitor for and prevent asymptomatic hypo- and hyperglycemia. Patients who take less frequent injections and those who take oral agents or use nutrition therapy should monitor their blood glucose levels to help achieve glycemic goals. Physicians should routinely evaluate patients' technique and instruct them on how to use testing data to adjust their therapy.
To assess treatment effectiveness, the A1C test should be performed at least twice per year in patients who are meeting treatment goals and who have stable glycemic control. Patients whose therapy has changed and those who are not meeting treatment goals should be tested quarterly. Conditions that affect erythrocyte turnover (e.g., hemolysis, blood loss) and hemoglobin variants must be considered, especially when the A1C result does not correlate with the patient's clinical situation.
Blood Pressure control
Blood pressure should be measured at every routine visit. Patients with systolic blood pressure of at least 130 mm Hg or diastolic blood pressure of at least 80 mm Hg should have blood pressure confirmed on a separate day. Patients with hypertension (i.e., systolic blood pressure of 140 mm Hg or diastolic blood pressure of 90 mm Hg) should receive drug therapy in addition to lifestyle and behavioral therapy. Multiple agents generally are required to achieve blood pressure targets. Patients with a systolic blood pressure of 130 to 139 mm Hg or a diastolic blood pressure of 80 to 89 mm Hg should receive lifestyle and behavioral therapy alone for a maximum of three months; if targets are not achieved, they should be treated with pharmacologic agents that block the renin-angiotensin system.
Initial drug therapy for patients with a blood pressure of 140/90 mm Hg should include a drug class proven to reduce cardiovascular events in patients with diabetes (i.e., angiotensin-converting enzyme [ACE] inhibitors, angiotensin receptor blockers [ARBs], beta blockers, diuretics, and calcium channel blockers). 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. A thiazide diuretic may be added if needed to achieve blood pressure targets.
Lipid control
Adult patients should be tested for lipid disorders at least annually. In adults with low-risk lipid values, assessments may be repeated every two years. 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. In persons without overt cardiovascular disease, the primary goal is a low-density lipoprotein (LDL) cholesterol level of less than 100 mg per dL (2.60 mmol per L). For persons older than 40 years, statin therapy to achieve an LDL reduction of 30 to 40 percent, regardless of baseline LDL levels, is recommended. Persons younger than 40 years but at increased risk because of other cardiovascular risk factors who do not achieve lipid goals with lifestyle modifications alone should receive pharmacologic therapy.
All patients with overt cardiovascular disease should be treated with a statin to achieve an LDL reduction of 30 to 40 percent. A lower LDL cholesterol goal of 70 mg per dL (1.80 mmol per L), using a high dose of a statin, is an option. Triglyceride levels should be less than 150 mg per dL (1.70 mmol per L), and high-density lipoprotein (HDL) cholesterol levels should be greater than 40 mg per dL (1.05 mmol per L). 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 cardiovascular event reduction or safety.
medical nutrition therapy
Persons with diabetes should receive individualized medical nutrition therapy to achieve treatment goals. Prevention and treatment of chronic complications of diabetes can be achieved by attaining optimal blood glucose, A1C, LDL, HDL, and triglyceride levels, and optimal blood pressure and body weight (Table 3). Because of the complexity of nutrition issues, a registered dietitian who is skilled in implementing nutrition therapy in patients with diabetes should be part of the medical team.
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TABLE 3 Summary of Recommendations for Adults with Diabetes |
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Glycemic control A1C level less than 7 percent* Blood pressure less than 130/80 mm Hg Peak postprandial capillary plasma glucose level less than 180 mg per dL (10 mmol per L)† Preprandial capillary plasma glucose level 90 to 130 mg per dL (5.0 to 7.2 mmol per L) Lipid levels‡ HDL cholesterol level greater than 40 mg per dL (1.05 mmol per L)§ LDL cholesterol level less than 100 mg per dL (2.60 mmol per L) Triglyceride level less than 150 mg per dL (1.70 mmol per L) Key concepts in setting glycemic goals A1C is the primary target for glycemic control. Certain populations (e.g., children, pregnant women, elderly persons) require special considerations. Goals should be individualized. Less intensive glycemic goals may be indicated in persons with severe or frequent hypoglycemia. More stringent glycemic goals (i.e., normal A1C level of less than 6 percent) may further reduce complications at the cost of increased risk of hypoglycemia. Postprandial glucose levels may be targeted if A1C goals are not met despite reaching preprandial glucose goals. |
| HDL = high-density lipoprotein; LDL = low-density lipoprotein. *-Referenced to a nondiabetic range of 4 to 6 percent using a Diabetes Control and Complications Trial-based assay. †-Postprandial glucose measurement should be made one to two hours after the beginning of the meal. ‡-Current guidelines suggest that in patients with triglyceride levels of at least 200 mg per dL (2.26 mmol per L), the non-HDL cholesterol level be used (total cholesterol level minus HDL cholesterol level). The goal is 130 mg per dL (3.35 mmol per L) or less. §-It has been suggested that the HDL cholesterol goal for women be increased by 10 mg per dL (0.25 mmol per L). Adapted with permission from American Diabetes Association. Standards of medical care in diabetes-2006. Diabetes Care 2006;29(suppl 1):S10. |
Monitoring total grams of carbohydrate, whether by use of exchanges or carbohydrate counting, is a key strategy in achieving glycemic control. The use of the glycemic index may provide additional benefit. Low-carbohydrate diets (i.e., total carbohydrate intake of less than 130 g per day) are not recommended for persons with diabetes. To reduce the risk of nephropathy, protein intake should be limited to 0.8 g per kg in patients with any degree of chronic kidney disease. Saturated fat intake should be limited to less than 7 percent of total calories, and intake of trans fat should be minimized. Nonnutritive sweeteners are safe when consumed within the acceptable daily intake levels established by the U.S. Food and Drug Administration. Alcohol intake should be limited to one drink per day for women and two drinks per day for men.
Routine antioxidant supplementation is not advised because of concerns about effectiveness and long-term safety. Chromium supplementation has not been proven to benefit patients with diabetes and is not recommended.
weight management
Overweight and obesity are strongly linked to the development of type 2 diabetes and can complicate its management. Obesity also is an independent risk factor for hypertension, dyslipidemia, and cardiovascular disease, which is the major cause of death in persons with diabetes. Patents with a BMI of at least 25 kg per m2 and who have diabetes or are at risk of developing diabetes should be counseled to lose weight. The primary approach should be lifestyle change, which includes a reduction in energy intake and an increase in physical activity. A moderate decrease in caloric balance (i.e., 500 to 1,000 kcal per day) will result in a slow but progressive weight loss of 1 to 2 lb (2.2. to 4.4 kg) per week. For most patients, weight-loss diets should supply at least 1,000 to 1,200 kcal per day for women and 1,200 to 1,600 kcal per day for men.
Physical activity recommendations should be personalized based on the patient's willingness and ability to increase his or her activity level; the duration and frequency should be increased gradually. At least 150 minutes per week of moderate-intensity physical activity may improve glycemic control and reduce the risk of cardiovascular disease.
self-management education
Persons with diabetes should receive self-management education according to national standards when their diabetes is diagnosed and as needed afterward. Education should address psychosocial issues, because emotional well-being is strongly associated with positive outcomes. Self-management education helps patients optimize metabolic control, prevent and manage complications of diabetes, and maximize their quality of life.
Practice Guideline Briefs
AGA Releases Position Statement on Management of Hepatitis C
The demand to manage hepatitis C virus (HCV) infection has increased over the past decade, and current predictions are that HCV-associated morbidity and mortality rates will escalate in the next 20 years. The American Gastroenterological Association (AGA) has released a review and position statement on the management of HCV infection. The report was published in the January 2006 issue of Gastroenterology.
Routine screening is not necessary for asymptomatic adults with a low probability of infection. Persons in high-risk groups (e.g., injection drug users, immigrants from countries with high rates of infection) should be tested for HCV.
Potential candidates for antiviral therapy include patients who have a reactive enzyme immunoassay for antibody to HCV and those with HCV RNA or compensated liver disease. Elevated alanine transaminase and aspartate transaminase levels are not required for therapy.
Preferred therapy for previously untreated patients with HCV infection consists of a weekly subcutaneous injection of pegylated interferon alfa and oral ribavirin (Rebetol) taken daily. Pegylated interferon is considered the best treatment for patients with indications for antiviral therapy but who have contraindications to ribavirin. Two pegylated interferon alfa preparations are available: pegylated interferon alfa-2a (Pegasys), which is administered at a fixed 180-mcg dose, and pegylated interferon alfa-2b (PEG-Intron), which is administered at a dose of 1.5 mcg per kg.
HCV RNA levels should be monitored using the same quantitative amplification assay at baseline and 12 weeks. An early virologic response (i.e., a reduction in HCV RNA levels of at least 2-log10 within the first 12 weeks of therapy) is a valuable clinical milestone. Without the early virologic response, the chance of sustained virologic response is 3 percent or less. During therapy, clinical and virologic monitoring should be performed at intervals of once per month to once every three months.
Treatment recommendations may vary for other patients, including those with cirrhosis, acute hepatitis C, hematologic disorders, end-stage renal disease, extrahepatic disease, and human immunodeficiency virus, as well as patients who are injection-drug or alcohol users, have had a liver transplant, or have relapsed or did not respond to previous HCV therapy. Treatment is not recommended for patients younger than three years.
CDC Releases Report on Early- and Late-Onset Neonatal GBS Infection
In 2002 the Centers for Disease Control and Prevention (CDC), the American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics recommended universal screening of pregnant women at 35 to 37 weeks' gestation for rectovaginal group B streptococcus (GBS) colonization; intrapartum antimicrobial prophylaxis was recommended for carriers. To assess the impact of this strategy, the CDC analyzed data from 1996 to 2004 from the Active Bacterial Core surveillance system. The report was published in the December 2, 2005, issue of Morbidity and Mortality Weekly Report and is available at http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5447a2.htm.
The data represented approximately 337,000 live births in 1996 to approximately 427,000 live births in 2004. GBS found in children between zero and six days of age was defined as early onset, and disease found in children between seven and 89 days of age was considered late onset. The CDC found that the incidence of early-onset GBS infection in 2004 decreased 31 percent from 2000 and 2001, the period just before the universal screening was implemented. The incidence of late-onset GBS infection remained the same from 1996 to 2004.
Although the absolute difference between blacks and whites in the incidence of early-onset infection declined 68 percent from 1993 (before the prevention guidelines were released) to 2003, racial disparities still exist. In 2004, the rates of late-onset GBS infection per 1,000 live births were 0.83 for blacks, 0.28 for whites, and 0.19 for infants of other races. Similarly, the rates of early-onset disease per 1,000 births were 0.73 for blacks, 0.26 for whites, and 0.15 for other races.
In both early- and late-onset GBS infection, the fatality ratio was highest for preterm infants (23 percent of infants with early-onset infection and 9 percent of those with late-onset infection). Of term infants, 4 percent with early-onset infections died, whereas no infants with late-onset infection died. Continued examination is needed to evaluate the effects of the 2002 guideline revision on early-onset infections and to determine the long-term effects of intrapartum use of antimicrobial agents on neonatal GBS infection.
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| Copyright © 2006 by the American
Academy of Family Physicians. |
