Alcohol consumption and the risk of coronary heart disease in postmenopausal women with diabetes: Women's Health Initiative Observational Study

Background Although several observational studies have consistently reported an inverse association between moderate alcohol consumption and risk of coronary heart disease (CHD), it is yet not well established if this association also exists among people with type 2 diabetes. The aim of this study is to evaluate the association between the frequency and quantity of alcohol intake and the risk of developing CHD among postmenopausal women with diabetes. Methods We conducted a prospective cohort study, which included 3,198 women with self-reported diabetes and without any history of cardiovascular disease at baseline, in the Women's Health Initiative Observational Study. Alcohol intake was assessed by a semiquantitative food frequency questionnaire. The primary outcome of this study was CHD, which was validated by medical record review. Cox proportional hazards regression was used to estimate the hazard ratio (HR) for the association of alcohol intake and risk of incident CHD while adjusting for several potential confounders. Results During the 22,546 person-years of follow-up, there were 336 incident cases of CHD. Both frequency and quantity of alcohol intake were inversely associated with the risk of developing CHD. Compared to nondrinkers, the multivariable HRs across categories of frequency of alcohol consumption (≤0.5, 0.5-2 and ≥2 drinks/week) were 0.89 (95% confidence intervals [CI]: 0.63, 1.26), 0.84 (95% CI: 0.56, 1.25) and 0.65 (95% CI: 0.43, 0.99), respectively (p for trend: 0.04). This association did not appear to differ based on the type of the alcoholic beverage consumed. Conclusions Moderate alcohol consumption of postmenopausal women with type 2 diabetes may have a benefit on CHD similar to that seen in postmenopausal nondiabetic women. The potential risks of alcohol on noncardiac outcomes may need consideration when recommending alcohol to women with diabetes.