Performance Characteristics of the New Definition of Diabetes

The Insulin Resistance Atherosclerosis Study

  1. Carlos Lorenzo, MD and
  2. Steven M. Haffner, MD
  1. From the Department of Medicine, University of Texas Health Science Center, San Antonio, Texas.
  1. Corresponding author: Carlos Lorenzo, lorenzo{at}


OBJECTIVE A1C ≥6.5% has been recently proposed as the defining criterion for diabetes. However, performance characteristics of this definition have not been described.

RESEARCH DESIGN AND METHODS In the Insulin Resistance Atherosclerosis Study, we compared new to previous definitions of diabetes: 1999 World Health Organization (DM1999WHO) and 2003 American Diabetes Association based on fasting glucose alone (DMFPG126).

RESULTS Participants with A1C ≥6.5%, DM1999WHO, and DMFPG126 were 44 (5.2%), 132 (15.4%), and 61 (7.1%), respectively. In individuals with DM1999WHO, mean, median, and interquartile range of A1C were 6.3, 5.9, and 5.5–6.6%, respectively; in individuals with DMFPG126, mean, median, and interquartile range of A1C were 7.0, 6.6, and 6.0–7.1%.

CONCLUSIONS A1C ≥6.5% identifies fewer individuals than DM1999WHO or DMFPG126. Studies are needed to determine that A1C ≥6.5% compromises neither blood pressure and lipid management in early diabetes nor the implementation of lifestyle interventions for diabetes prevention.


  • 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.

    • Received July 23, 2009.
    • Accepted October 20, 2009.
| Table of Contents