Midlife Alcohol Consumption and the Risk of Stroke in the Atherosclerosis Risk in Communities Study.

BACKGROUND AND PURPOSE: Alcohol consumption is common in the United States and may confer beneficial cardiovascular effects at light-to-moderate doses. The alcohol-stroke relationship remains debated. We estimated the relationship between midlife, self-reported alcohol consumption and ischemic stroke and intracerebral hemorrhage (ICH) in a biracial cohort.

METHODS: We examined 12,433 never and current drinkers in the Atherosclerosis Risk in Communities study, aged 45 to 64 years at baseline. Participants self-reported usual drinks per week of beer, wine, and liquor at baseline. We used multivariate Cox proportional hazards regression to assess the association of current alcohol consumption relative to lifetime abstention with incident ischemic stroke and ICH and modification by sex-race group. We modeled alcohol intake with quadratic splines to further assess dose-response relationships.

RESULTS: One third of participants self-reported abstention, 39% and 24%, respectively, consumed ≤3 and 4 to 17 drinks/wk, and only 5% reported heavier drinking. There were 773 ischemic strokes and 81 ICH over follow-up (median≈22.6 years). For ischemic stroke, light and moderate alcohol consumption were not associated with incidence (hazard ratios, 0.98; 95% CI, 0.79-1.21; 1.06, 0.84-1.34), whereas heavier drinking was associated with a 31% increased rate relative to abstention (hazard ratios, 1.31; 95% CI, 0.92-1.86). For ICH, moderate-to-heavy (hazard ratios, 1.99; 95% CI, 1.07-3.70), but not light, consumption increased incidence.

CONCLUSIONS: Self-reported light-to-moderate alcohol consumption at midlife was not associated with reduced stroke risk compared with abstention over 20 years of follow-up in the Atherosclerosis Risk in Communities study. Heavier consumption increased the risk for both outcomes as did moderate intake for ICH.