Diabetes as Risk Factor for Coronary Heart Disease in Women compared with Men
A previous pooled analysis suggested that women with diabetes are at substantially increased risk of fatal coronary heart disease (CHD) compared with affected men. Additional findings from larger and more contemporary studies have since published on the sex-specific associations between diabetes and incident CHD. We performed a systematic review with meta-analysis so as to provide the most reliable evidence of any sex difference in the effect of diabetes on subsequent risk of CHD.
METHODS:
PubMed MEDLINE was systematically searched for prospective population-based cohort studies published between on January 1, 1966 and February 13, 2013. Eligible studies had to have reported sex-specific estimates of the relative risk (RR) for incident CHD associated with diabetes, and its associated variability. Random effects meta-analyses with inverse variance weighting were used to obtain sex-specific RRs and their ratio (RRR).
RESULTS:
Data from 64 cohorts including 858,507 individuals and 28,203 incident CHD events were included. The RR for incident CHD associated with diabetes compared with no diabetes was 2.83 (95% confidence interval [CI]: 2.37, 3.38) in women and 2.11 (95% CI: 1.79, 2.50) in men. The multiple-adjusted RRR for incident CHD was 44% greater in women with diabetes than it was in men with diabetes (95% CI: 27; 63) with no significant heterogeneity between studies (I2=20%).
CONCLUSIONS:
Women with diabetes have more than a 40% greater risk of incident CHD compared with men with diabetes. Sex disparities in pharmacotherapy are unlikely to explain the excess risk in women. Instead, a greater deterioration in cardiovascular risk profile combined with more prolonged exposure to adverse levels of cardiovascular risk factors among pre-diabetic women compared with their male equivalents may be responsible for the excess risk of diabetes-related CHD in women. Future studies are warranted elucidate the mechanisms responsible for the substantial sex-difference in diabetes-related risk of CHD.