Comparison of Alzheimer's disease risk factors in white and African American families.

The associations between alcohol, smoking, and head injury and the risk of AD in 443 African American and 2,336 white participants in the MIRAGE Study were evaluated. Alcohol had a modest protective effect in whites (odds ratio [OR] = 0.82, 95% CI = 0.68 to 0.99), with a similar trend in African Americans (OR = 0.88, 95% CI = 0.54 to 1.4). Head trauma increased the risk of AD in whites (OR = 2.3, 95% CI = 1.8 to 3.0) and African Americans (OR = 2.9, 95% CI = 1.2 to 7.0). Smoking was not associated with AD risk in whites (OR = 0.88, 95% CI = 0.73 to 1.1) or African Americans (OR = 1.0, 95% CI = 0.69 to 1.5). These risks were similar across subsets stratified by the presence or absence of the APOE epsilon4 allele.