STROKE AND ALCOHOL INTAKE IN A HOSPITAL POPULATION - A CASE-CONTROL STUDY

Background and Purpose The aim of the study was to assess whether excessive alcohol intake is an independent risk factor for stroke. Methods A case-control study was undertaken in 200 consecutive ischemic and hemorrhagic stroke patients and 372 age and sex-matched control subjects (170 hospital-based and 202 community-based individuals). Data were collected through direct interview regarding demographics, risk factors for stroke, current daily alcohol consumption, and diagnosis of alcoholism. Blood was also taken to test the common biological markers of alcohol intake (erythrocyte mean cell volume, uric acid, aspartate aminotransferase, and gamma-glutamyl transferase). Results After controlling for the most significant risk factors (antecedent strokes, hypertension, diabetes, smoking) and using hospital control subjects for reference, we determined the risk of stroke to be 2.2 (95% confidence interval [CI], 1.2 to 4.0) in moderate drinkers (men, less than or equal to 60 g/d; women, less than or equal to 40 g/d) and 2.9 (95% CI, 1.4 to 6.1) in heavy drinkers (men, >60 g/d; women, >40 g/d). The corresponding risk values obtained when we compared case subjects and external control subjects were 1.4 (95% CI, 0.8 to 2.7) and 3.0 (95% CI, 1.3 to 7.0). Even with some fluctuations across groups, the risk did not change significantly after subgroup analysis in men, patients with first-ever stroke, patients with ischemic stroke, and after exclusion of subjects with risk factors for stroke. Compared with hospital and external control subjects, stroke patients included a higher proportion of heavy drinkers (26.6% versus 20.6% versus 10.8%), alcoholics (14.6% versus 7.7% versus 2.5%), and cases with abnormal erythrocyte mean cell volume (63.0% versus 47.6% versus 34.2%) or gamma-glutamyl transferase (35.5% versus 32.4% versus 12.9%). Mean alcohol consumption was 42.2 g/d in the case subjects, 30.8 g/d in the hospital control subjects, and 23.2 g/d in the external control subjects. Conclusions The study indicates that alcohol can be considered an independent risk factor for stroke in Italy.