Is acute alcohol ingestion a risk factor for ischemic stroke? Results of a controlled study in middle-aged and elderly stroke patients at three urban medical centers.

To assess the role of acute alcohol ingestion as a risk factor for cerebral infarction, we administered a pretested questionnaire to 205 middle-aged and elderly acute ischemic stroke patients and 410 outpatient controls matched by age, sex, race, and method of hospital payment. Paired Mantel-Haenszel analysis revealed that alcohol ingestion within 24 (p = 0.07) and 72 (p = 0.001) hours of stroke onset and medical histories of smoking (p less than 0.0001), hypertension (p less than 0.001), and transient ischemic attacks (p = 0.051) were more common among stroke index cases than controls. Matched multiple logistic analysis revealed that both hypertension (p less than 0.05) and smoking (p less than 0.05) were independently associated with stroke, while alcohol consumption was not. In analyses to assess the possibility of mutual confounding effects of independent variables, the effect of alcohol ingestion was lost when adjusting for smoking. We conclude that acute alcohol ingestion is not an independent risk factor for cerebral infarction in middle-aged and elderly patients. The apparent association between alcohol ingestion and ischemic stroke may be the result of the confounding effects of smoking.