Estimated number of adults with prediabetes in the US in 2000: opportunities for prevention.

OBJECTIVE To estimate the percent and number of overweight adults in the U.S. with prediabetes who would be potential candidates for diabetes prevention as per the American Diabetes Association Position Statement (12). RESEARCH DESIGN AND METHODS We analyzed data from the Third National Health and Nutrition Examination Survey (NHANES III; 1988-1994) and projected our estimates to the year 2000. We defined impaired glucose tolerance (IGT; 2-h glucose 140-199 mg/dl), impaired fasting glucose (IFG; fasting glucose 110-125 mg/dl), and prediabetes (IGT or IFG) per American Diabetes Association (ADA) criteria. The ADA recently recommended that all overweight people (BMI >or=25 kg/m(2)) who are >or=45 years of age with prediabetes could be potential candidates for diabetes prevention, as could prediabetic people aged >25 years with risk factors. In NHANES III, 2-h postload glucose concentrations were done only among subjects aged 40-74 years. Because we were interested in overweight people who had both the 2-h glucose and fasting glucose tests, we limited our estimates of IGT, IFG, and prediabetes to those aged 45-74 years. RESULTS-Overall, 17.1% of overweight adults aged 45-74 years had IGT, 11.9% had IFG, 22.6% had prediabetes, and 5.6% had both IGT and IFG. Based on those data, we estimated that in the year 2000, 9.1 million overweight adults aged 45-74 had IGT, 5.8 million had IFG, 11.9 million had prediabetes, and 3.0 million had IGT and IFG. CONCLUSIONS Almost 12 million overweight individuals aged 45-74 years in the U.S. may benefit from diabetes prevention interventions. The number will be substantially higher if estimation is extended to individuals aged >75 and 25-44 years.