Contributions of A1c, fasting plasma glucose, and 2-hour plasma glucose to prediabetes prevalence: NHANES 2011-2014

Abstract

Purpose: Our goal was to characterize the contributions of A1c, fasting plasma glucose, and 2-hour plasma glucose to prediabetes prevalence and to characterize how those contributions differ among U.S. population subgroups.

Methods: In the 2011-2014 National Health and Nutrition Examination Survey, a nationally representative sample of the U.S. population, among participants without diabetes (N = 3387), we created area-proportional three-Venn diagrams showing the proportion above the prediabetes cutpoint for each of the three markers in the overall population and in subgroups defined by age, race/ethnicity, sex, and body mass index.

Results: In the overall population, 28.3% had fasting plasma glucose above the prediabetes cutpoint, 21.7% had A1c above the prediabetes cutpoint, and 13.3% had 2-hour plasma glucose above the prediabetes cutpoint. Adolescents and young adults tended to have only one marker exceed the prediabetes cutpoint, while older age groups tended to have multiple markers above the prediabetes cutpoint. For non-Hispanic whites, non-Hispanic blacks, non-Hispanic Asians, and Mexican-Americans, the unadjusted total percent above the A1c cutpoint was 19.3%, 36.4%, 20.5%, and 21.4%, respectively.

Conclusions: We provide a graphic reference showing fasting plasma glucose was the largest contributor to prediabetes prevalence in the overall population, followed by A1c and then 2-hour plasma glucose.

Keywords: Fasting glucose; HbA1c; NHANES; OGTT; Prediabetes.