Diabetes associated with higher risk of coronary heart disease in women than men

Women with diabetes have a more than 40% higher risk of incident coronary heart disease than men, a new meta-analysis found.

Researchers reviewed PubMed for prospective cohort studies published between 1966 and early 2013 that included sex-specific relative risk estimates for incident coronary heart disease (CHD) in people with and without diabetes. Multiple adjusted results were used in the primary analyses; at least one other risk factor besides age had to be used in adjustment. Researchers used random-effects meta-regression analyses to obtain sex-specific relative risks. Their analysis included data from 64 cohorts, 858,507 people, and 28,203 incident CHD events.

Overall, the relative risk (RR) for incident CHD associated with diabetes versus no diabetes was 2.82 in women (95% CI, 2.35 to 3.38) and 2.16 in men (95% CI, 1.82 to 2.56). The multiple-adjusted relative risk ratio for incident CHD was 44% higher in women than men with diabetes, with no significant heterogeneity between studies. The sex difference in diabetes-related risk remained consistent across subgroups defined by age and region and didn't change after exclusion of non-fatal CHD incidents. Results were published in the May Diabetologia.

Past studies have suggested women have more undertreatment of cardiovascular risk factors than men, but the authors said they don't think this fully accounts for the excess CHD risk in diabetic women. Instead, they suspect the excess risk for women may result from “a greater deterioration in cardiovascular risk profile combined with more prolonged exposure to adverse levels of cardiovascular risk factors among prediabetic women,” they wrote.

A cross-sectional study of 680 primary care patients with type 2 diabetes, published online April 15 by Diabetes Technology & Therapeutics, found that composite control of cardiovascular risk factors was significantly lower in women than men (5.9% control in women vs. 17.3% in men; adjusted odds ratio, 2.90). The composite factors measured were HbA1c level of <7%, blood pressure of <130/80 mm Hg, and low-density lipoprotein level of <100 mg/dL (2.6 mmol/L). “It is imperative that women are informed about [cardiovascular disease] risk factors, educated on how to reduce them, and aggressively treated to avoid adverse outcomes,” the authors concluded.