Sex differences in risk for coronary heart disease mortality associated with diabetes and established coronary heart disease

BACKGROUND: The sex-specific independent effect of diabetes mellitus and established coronary heart disease (CHD) on subsequent CHD mortality is not known. METHODS: This is an analysis of pooled data (n = 5243) from the Framingham Heart Study and the Framingham Offspring Study with follow-up of 20 years. At baseline (1971-1975), 134 men and 95 women had diabetes, while 222 men and 129 women had CHD. Risk for CHD death was analyzed by proportional hazards models, adjusting for age, hypertension, serum cholesterol levels, smoking, and body mass index. The comparative effect of established CHD vs diabetes on the risk of CHD mortality was tested by testing the difference in log hazards. RESULTS: The adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for death from CHD were 2.1 (95% CI, 1.3-3.3) in men with diabetes only, and 4.2 (95% CI, 3.2-5.6) in men with CHD only compared with men without diabetes or CHD. The HR for CHD death was 3.8 (95% CI, 2.2-6.6) in women with diabetes, and 1.9 (95% CI, 1.1-3.4) in women with CHD. The difference between the CHD and the diabetes log hazards was +0.73 (95% CI, 0.72-0.75) in men and -0.65 (95% CI, -0.68 to -0.63) in women. CONCLUSIONS: In men, established CHD signifies a higher risk for CHD mortality than diabetes. This is reversed in women, with diabetes being associated with greater risk for CHD mortality. Current treatment recommendations for women with diabetes may need to be more aggressive to match CHD mortality risk.