Gender differences in the impact of diabetes on mortality in patients with established coronary artery disease: A report from the Eastern Taiwan integrated health care delivery system of Coronary Heart Disease (ET-CHD) registry, 1997–2006

Objectives The effect of type 2 diabetes mellitus (DM) on mortality was more pronounced in women than men with coronary artery disease (CAD) in the pre-stent era before 1996. However this relationship is controversial in the post-stent era. Methods We studied a cohort of 1073 patients with angiographically defined CAD from the Eastern Taiwan integrated health care delivery system of Coronary Heart Disease (ET-CHD) registry during 1997–2003 in Tzu-Chi General Hospital, Hualien, Taiwan. To evaluate gender-specific DM effect on mortality, the subjects were divided into 4 groups: diabetic women ( n = 147), non-diabetic women ( n = 127), diabetic men ( n = 239), and non-diabetic men ( n = 560). At a mean follow-up of 5.4 years, cardiac and all-cause mortality were the primary end points. Results Annual total mortality rates were 10.2%, 5.1%, 7.2%, and 4.8%; annual cardiac mortality rates were 8.2%, 3.0%, 4.3%, and 2.6% for diabetic women, non-diabetic women, diabetic men, and non-diabetic men, respectively. Multivariate Cox regression models, adjusted for possible confounders showed that gender-specific hazard ratios (HRs) of DM for total mortality were 2.02 (95% CI: 1.32–3.09), and 1.72 (95% CI: 1.32–2.25) for women and men, respectively. The HRs for total mortality associated with diabetes were not different between women and men ( p = 0.53). Similarly, adjusted gender-specific HRs of DM for cardiac mortality were 2.46 (95% CI: 1.45–4.19) for women, and 1.83 (95% CI: 1.28–2.62) for men, which were also not significantly different ( p = 0.36). Conclusions Among patients with CAD, the impact of DM on mortality was consistently higher in women than in men, but the differences across sexes were not statistically significant after 1996 in Taiwan.