[Sysop]

Objective: We examined prevalences of previously diagnosed diabetes, and undiagnosed diabetes and high risk for diabetes using recently suggested A1c criteria, in the U.S. during 2003-2006. We compared these prevalences to those in earlier surveys and those using glucose criteria.
Research Design and Methods: In 2003-2006, the National Health and Nutrition Examination Survey included a probability sample of 14,611 individuals aged ≥12 years. Participants were classified on glycemic status by interview for diagnosed diabetes and by A1c, fasting, and 2-hour glucose challenge values measured in subsamples.
Results:
Using A1c criteria, the crude prevalence of total diabetes in adults age ≥20 years was 9.6% (20.4 million), of which 19.0% was undiagnosed (7.8% diagnosed, 1.8% undiagnosed using A1c ≥6.5%). Another 3.5% of adults (7.4 million) were at high risk for diabetes (A1c 6.0-2 times higher in non-Hispanic blacks and Mexican Americans vs. non-Hispanic whites for diagnosed, undiagnosed, and total diabetes (p2 times higher in non-Hispanic blacks vs. non-Hispanic whites and Mexican Americans (p