Light-to-moderate alcohol consumption and risk of sudden cardiac death in women

BACKGROUND Moderate alcohol intake is associated with lower risk of coronary heart disease (CHD), but the association with sudden cardiac death (SCD) is less clear. In men, heavy alcohol consumption may increase risk of SCD, whereas light-to-moderate alcohol intake may lower risk. There are no parallel data among women. OBJECTIVE The purpose of this study was to assess the association between alcohol intake and risk of SCD among women and to investigate how this risk compared to other forms of CHD. METHODS We conducted a prospective cohort study among 85,067 women from the Nurses' Health Study who were free of chronic disease at baseline. Alcohol intake was assessed every 4 years through questionnaires. Primary endpoints included SCD, fatal CHD, and nonfatal myocardial infarction. RESULTS We found a U-shaped association between alcohol intake and risk of SCD, with the lowest risk among women who drank 5.0-14.9 g/day of alcohol (P for quadratic trend = 0.02). Compared to abstainers, the multivariate relative risk (95% confidence interval) for SCD was 0.79 (0.55-1.14) for former drinkers, 0.77 (0.57-1.06) for 0.1-4.9 g/day, 0.64 (0.43-0.95) for 5.0-14.9 g/day, 0.68 (0.38-1.23) for 15.0-29.9 g/day, and 1.15 (0.70-1.87) for >= 30.0 g/day. In contrast, the relationship of alcohol intake and nonfatal and fatal CHD was more linear (P for linear trend <.001). CONCLUSION In this cohort of women, the relationship between light-to-moderate alcohol intake and SCD is U-shaped, with a nadir at 5.0-14.9 g/day. Low levels of alcohol intake do not raise the risk of SCD and may lower risk in women.