OBJECTIVE—To compare the prevalence of prediabetes using A1C, fasting plasma glucose
(FPG), and oral glucose tolerance test (OGTT) criteria, and to examine the degree of agreement
between the measures.
RESEARCH DESIGN AND METHODS—We used the 2005–2008 National Health and
Nutrition Examination Surveys to classify 3,627 adults aged $18 years without diabetes according to their prediabetes status using A1C, FPG, and OGTT. We compared the prevalence of
prediabetes according to different measures and used conditional probabilities to examine agreement between measures.
RESULTS—In 2005–2008, the crude prevalence of prediabetes in adults aged $18 years was
14.2% for A1C 5.7–6.4% (A1C5.7), 26.2% for FPG 100–125 mg/dL (IFG100), 7.0% for FPG
110–125 mg/dL (IFG110), and 13.7% for OGTT 140–199 mg/dL (IGT). Prediabetes prevalence
varied by age, sex, and race/ethnicity, and there was considerable discordance between measures
of prediabetes. Among those with IGT, 58.2, 23.4, and 32.3% had IFG100, IFG110, and A1C5.7,
respectively, and 67.1% had the combination of either A1C5.7 or IFG100.
CONCLUSIONS—The prevalence of prediabetes varied by the indicator used to measure
risk; there was considerable discordance between indicators and the characteristics of individuals
with prediabetes. Programs to prevent diabetes may need to consider issues of equity, resources,
need, and efficiency in targeting their efforts.