Coronary Artery Calcification in Type 2 Diabetes and Insulin Resistance

Coronary Artery Calcification in Type 2 Diabetes and Insulin Resistance The Framingham Offspring Study James B. Meigs , MD, MPH 1 , Martin G. Larson , SCD 2 , Ralph B. D’Agostino , PHD 3 , Daniel Levy , MD 2 , Melvin E. Clouse , MD 4 , David M. Nathan , MD 5 , Peter W. F. Wilson , MD 6 and Christopher J. O’Donnell , MD, MPH 2 7 1 General Medicine Division and Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 2 National Heart, Lung and Blood Institute’s Framingham Heart Study, Framingham, Massachusetts 3 Department of Mathematics, Statistics, and Consulting Unit, Boston University, Boston, Massachusetts 4 Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 5 Diabetes Unit and Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 6 Framingham Heart Study, Boston University School of Medicine, Framingham, Massachusetts 7 Cardiology Division and Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts Abstract OBJECTIVE —To assess risk for subclinical coronary atherosclerosis using electron beam- computed tomography in subjects with or without insulin resistance and with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT/impaired fasting glucose [IFG]) or type 2 diabetes. RESEARCH DESIGN AND METHODS —We categorized glucose tolerance by type 2 diabetes therapy (diagnosed diabetes) or with an oral glucose tolerance test (OGTT) (IFG, IGT, and OGTT-detected diabetes) and insulin resistance as an elevated fasting insulin level, in subjects attending the fifth examination (1991–1995) of the Framingham Offspring Study. A representative subset of subjects without clinical atherosclerosis was selected for electron beam computed tomography in 1998–1999 from age- and sex-stratified quintiles of the Framingham risk score. The presence of subclinical atherosclerosis was defined as the upper quartile of the Agatston score distribution (score > 170). We assessed risk for subclinical atherosclerosis using multivariable logistic regression. RESULTS —Of 325 subjects aged 31–73 years, 51% were men, 11.2% had IFG/IGT, and 9.9% had diabetes (2.8% with diagnosed diabetes); 14.5% had insulin resistance. Compared with NGT, subjects with IFG/IGT tended to be more likely (adjusted odds ratio 1.5, 95% CI 0.7–3.4) and those with diabetes were significantly more likely (2.7, 1.2–6.1) to hav