Effect of Type 1 Diabetes on the Gender Difference in Coronary Artery Calcification: a Role for Insulin Resistance?

The Coronary Artery Calcification in Type 1 Diabetes (CACTI) Study

  1. Dana Dabelea1,
  2. Gregory Kinney1,
  3. Janet K. Snell-Bergeon1,
  4. John E. Hokanson1,
  5. Robert H. Eckel2,
  6. James Ehrlich3,
  7. Satish Garg4,
  8. Richard F. Hamman1 and
  9. Marian Rewers13
  1. 1Department of Preventive Medicine and Biometrics, University of Colorado Health Sciences Center, Denver, Colorado
  2. 2Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado
  3. 3Colorado Heart Imaging Center, Denver, Colorado
  4. 4Barbara Davis Center for Childhood Diabetes, Denver, Colorado
  1. Address correspondence to Dana Dabelea, MD, PhD, Department of Preventive Medicine and Biometrics, University of Colorado Health Sciences Center, 4200 East 9th Ave., Campus Box C245, Denver, CO 80262. E-mail: dana.dabelea{at}uchsc.edu

Abstract

The objective of this is study was to examine whether estimated insulin resistance and insulin resistance-related factors are associated with coronary artery calcification (CAC) in 1,420 asymptomatic participants in the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study. A total of 656 patients with type 1 diabetes and 764 control subjects aged 20–55 years were examined. CAC was assessed by electron-beam computed tomography. Insulin resistance was computed with linear regression based on an equation previously validated in clamp studies on type 1 diabetic adults. Insulin resistance was associated with CAC (OR 1.6 in type 1 diabetes and 1.4 in control subjects, P < 0.001), independent of coronary artery disease risk factors. There was a male excess of CAC in control subjects (OR 2.7, adjusted for age, smoking, and LDL and HDL cholesterol levels) and in type 1 diabetic patients (OR 2.2, adjusted for the same factors and diabetes duration). After adjusting for insulin resistance, the CAC male excess in diabetic patients decreased from OR 2.2 (P < 0.001) to 1.8 (P = 0.04). After adjustment for waist-to-hip ratio, waist circumference, or visceral fat, the gender difference in CAC was not significant in diabetic subjects. In conclusion, gender differences in insulin resistance-associated fat distribution may explain why type 1 diabetes increases coronary calcification in women relatively more than in men.

Footnotes

    • Accepted July 28, 2003.
    • Received February 14, 2003.
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