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used various other terms to describe prediabetes. e use of different terms might have produced confusion among persons over what their health-care providers diagnosed.
e results of this analysis also might indicate that a large
percentage of persons with prediabetes have not been tested or diagnosed. e tests used to screen for prediabetes are the same as those used to screen for diabetes, and the population at risk for prediabetes is the same population as that at risk for type 2 diabetes. Hence, screening recommendations for prediabetes are essentially the same as those for diabetes (3).
e American Diabetes Association has recommended that
testing for prediabetes and diabetes be considered for adults who meet certain criteria (Box) (8).
e Diabetes Prevention Program intervention trial showed
that diet and exercise can lower the incidence of type 2 diabe- tes by 58% over 3 years among those at high risk for diabetes (5). Trial participants lost weight by reducing dietary fat and calories and by exercising at least 30 minutes a day, 5 days a week. e American Diabetes Association recommends that clinicians counsel patients with prediabetes on weight loss of 5–10% of body weight and on increasing physical activity to at least 150 minutes of moderate activity (e.g., walking) per week. Metformin administration should be considered under certain circumstances (8). However, the results in this report indicate that, although 42% of adults with prediabetes tried to lose or control weight, reduce fat or calories, and increase physical activity, one fourth did not engage in any of these risk-reduction activities.
e findings in this report are subject to at least two limita-
tions. First, NHIS interviews are household based and do not include persons who are institutionalized, including those living in nursing homes. Second, the 2006 NHIS questions regarding self-reported prediabetes were asked for the first time. Hence, no previous studies are available for comparison and validation.
Interventions to prevent or delay onset of type 2 diabetes in persons with prediabetes are feasible and cost effective, and lifestyle interventions are more cost effective than medications (9). e gap in prevalence between those with prediabetes and those aware of their condition presents an opportunity to reduce the burden of diabetes by increasing awareness of prediabetes and encouraging adoption of healthier lifestyles and risk-reduction activities.
Cowie CC, Rust KF, Byrd-Holt DD, et al. Prevalence of diabetes and impaired fasting glucose in adults in the U.S. population: National Health and Nutrition Examination Survey, 1999–2002. Diabetes Care 2006;29:1263–8.
Harris MI, Flegal KM, Cowie CC, et al. Prevalence of diabetes, impaired fasting glucose, and impaired glucose tolerance in U.S. adults. e ird National Health and Nutrition Examination Surve , 1998–1994. Diabetes Care 1998;21:518–24.
BOX. Criteria for testing for prediabetes and diabetes in asymptomatic adults
Testing should be considered in all adults who are overweight (body mass index >25 kg/m2*) and have any of the following additional risk factors:
first-degree relative with diabetes;
members of a high-risk ethnic population (e.g., African American, Latino, Native American, Asian American, and Pacific Islander);
women who delivered a baby weighing >9 lb or diagnosed with gestational diabetes;
hypertension (>140/90 mmHg or on therapy for hypertension);
HDL cholesterol level <35 mg/dL (0.90 mmol/L) and/or a triglyceride level >250 mg/dL (2.82 mmol/L);
women with polycystic ovarian syndrome;
impaired glucose tolerance or impaired fasting glucose on previous testing;
other clinical conditions associated with insulin resis- tance (e.g., severe obesity and acanthosis nigricans); or
history of cardiovascular disease.
In the absence of these risk factors, testing for predia- betes and diabetes should begin at age 45 years
If results are normal, testing should be repeated at least at 3-year intervals, with consideration of more frequent testing depending on initial results and risk status.
SOURCE: American Diabetes Association. Standards of medical care in diabetes—2008. Diabetes Care 2008;31(Suppl 1):S12–54.
At-risk body mass index might be lower in certain populations.
Nathan DM, Davidson MB, DeFronzo RA, et al. Impaired fasting glucose and impaired glucose tolerance: implications for care. Diabetes Care 2007;30:753–9.
Coutinho M, Gerstein HC, Wang Y, Yusuf S. e relationship between glucose and incident cardiovascular events. A metaregression analysis of published data from 20 studies of 95,783 individuals followed for 12.4 years. Diabetes Care 1999;22:233–40.
Knowler WC, Barrett-Conner E, Fowler SE, et al; Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002; 346:393–403.
CDC. National Health Interview Surve , 2006. Questionnaires, datasets, and related documentation. Available at http://www.cdc.gov/nchs/nhis.htm.
Graubard BI, Korn EL. Predictive margins with survey data. Biometrics 1999;55:652–9.
American Diabetes Association. Standards of medical care in diabetes—
Diabetes Care 2008;31(Suppl 1):S12–54.
Herman WH, Hoerger TJ, Brandle M, et al; Diabetes Prevention Program Research Group. The cost-effectiveness of lifestyle modification or metformin in preventing type 2 diabetes in adults with impaired glucose tolerance. Ann Intern Med 2005;142:323–32.