The effect of type 1 diabetes mellitus on the gender difference in coronary artery calcification

OBJECTIVES To examine whether the gender difference in coronary artery calc ification, a measure of atherosclerotic plaque burden, is lost in type 1 di abetic patients, and whether abnormalities in established coronary heart di sease risk factors explain this. BACKGROUND Type 1 diabetes abolishes the gender difference in coronary hear t disease mortality because it is associated with a greater elevation of co ronary disease risk in women than men. The pathophysiological basis of this is not understood. METHODS Coronary artery calcification and coronary risk factors were compar ed in 199 type 1 diabetic patients and 201 nondiabetic participants of simi lar age (30 to 55 years) and gender (50% female) distribution. Only one sub ject had a history of coronary disease. Calcification was measured with ele ctron beam computed tomography. RESULTS In nondiabetic participants there was a large gender difference in calcification prevalence (men 54%, women 21%, odds ratio 4.5, p < 0.001), h alf of which was explained by established risk factors (odds ratio after ad justment = 2.2). Diabetes was associated with a greatly increased prevalenc e of calcification in women (47%), but not men (52%), so that the gender di fference in calcification was lost (p = 0.002 for the greater effect of dia betes on calcification in women than men). On adjustment for risk factors, diabetes remained associated with a threefold higher odds ratio of calcific ation in women than men (p = 0.02). CONCLUSIONS In type 1 diabetes coronary artery calcification is greatly inc reased in women and the gender difference in calcification is lost. Little of this is explained by known coronary risk factors. (C) 2000 by the Americ an College of Cardiology.