Gender difference in the impact of type 2 diabetes on coronary heart disease risk.

OBJECTIVE To explain the stronger effect of type 2 diabetes on the risk of coronary heart disease (CHD) in women compared with men. RESEARCH DESIGN AND METHODS The study population consisted of 1,296 nondiabetic subjects and 835 type 2 diabetic subjects aged 45-64 years without cardiovascular disease. The end points were CHD death and a major CHD event (CHD death or nonfatal myocardial infarction). The follow-up time was 13 years. RESULTS Major CHD event rate per 1,000 person-years was 11.6 in nondiabetic men, 1.8 in nondiabetic women, 36.3 in diabetic men, and 31.6 in diabetic women. The diabetes-related hazard ratio for a major CHD event from the Cox model, adjusted for age and area of residence, was 2.9 (95% CI 2.2-3.9) in men and 14.4 (8.4-24.5) in women, and after further adjustment for cardiovascular risk factors, 2.8 (2.0-3.7) and 9.5 (5.5-16.9), respectively. The burden of conventional risk factors in the presence of diabetes was greater in women than in men at baseline. Prospectively, elevated blood pressure, low HDL cholesterol, and high triglycerides contributed to diabetes-related CHD risk more in women than in men. However, after adjusting for conventional risk factors, a substantial proportion of diabetes-related CHD risk remained unexplained in both genders. CONCLUSIONS The stronger effect of type 2 diabetes on the risk of CHD in women compared with men was in part explained by a heavier risk factor burden and a greater effect of blood pressure and atherogenic dyslipidemia in diabetic women.