Elevated A1C in Adults Without a History of Diabetes in the U.S.
- Elizabeth Selvin, PHD, MPH1,2,
- Hong Zhu3 and
- Frederick L. Brancati, MD, MHS1,2
- 1Department of Epidemiology and the Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland;
- 2Division of General Internal Medicine, Department of Medicine, The Johns Hopkins University, Baltimore, Maryland;
- 3Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
- Corresponding author: Elizabeth Selvin, lselvin{at}jhsph.edu
Abstract
OBJECTIVE The purpose of this study was to examine the prevalence and correlates of elevated A1C in a large, nationally representative sample of adults without diabetes in the U.S.
RESEARCH DESIGN AND METHODS We analyzed data from 15,934 participants aged ≥20 years without diagnosed diabetes who had A1C measurements in the 1999–2006 National Health and Nutrition Examination Survey, a cross-sectional and nationally representative sample of the U.S. population.
RESULTS The overall prevalence of A1C >6% was 3.8%, corresponding to 7.1 million adults without diabetes in the U.S. population. Approximately 90% of these individuals had fasting glucose ≥100 mg/dl. Older age, male sex, non-Hispanic black race/ethnicity, hypercholesterolemia, higher BMI, and lower attained education were significantly associated with having a higher A1C level even among individuals with normal fasting glucose (<100 mg/dl) and after multivariable adjustment.
CONCLUSIONS A single elevated A1C level (A1C >6%) is common in the general population of adults without a history of diabetes and is highly reliable for the detection of elevated fasting glucose. Nondiabetic adults with elevated A1C are likely to have impaired fasting glucose and an array of other risk factors for type 2 diabetes and cardiovascular disease.
Footnotes
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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- Received September 16, 2008.
- Accepted January 20, 2009.
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Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/licenses/by-nc-nd/3.0/ for details.
- © 2009 by the American Diabetes Association.
