A cross-ethnic analysis of risk factors for AD in white Hispanics and white non-Hispanics

Background: The prevalence of AD appears to vary widely in different ethnic groups. Certain risk factors for AD are well established for the general population, but there is little information regarding the relevance of these risk factors in specific ethnic groups. Objective: The authors examined the risk of AD associated with the APOE-epsilon 4 allele, the APOE-epsilon 2 allele, smoking, alcohol consumption, history of hypertension, low educational level, estrogen replacement therapy, and history of head trauma with loss of consciousness among samples of white non-Hispanics (WNH) (392 AD patients, 202 normal subjects) and white Hispanics (WHIS) (188 AD patients, 84 normal controls). Design: This was a case-control study of patients evaluated at an outpatient memory disorders clinic and control subjects recruited from a free memory screening offered to the community. Results: Increased risk for AD was associated with the APOE-epsilon 4 allele after controlling for age, education, and gender among WNH (OR = 3.5; 95% CI = 2.3 to 5.5) and WHIS (OR = 3.1; 95% CI = 1.7 to 5.8). No protective effect was conferred by the APOE-epsilon 2 allele, although this relationship approached significance among WNH (p = 0.02). Low levels of education increased the risk for AD among WNH (OR = 3.1; 95% CI = 1.8 to 5.9) but not WHIS. Alcohol use and hypertension approached significance as risk factors in WNH (p < 0.05) but not WHIS. Estrogen replacement treatment approached significance as a protective factor in both ethnic groups (p < 0.05). Conclusions: Although the APOE-epsilon 4 allele is a risk factor for AD among WHIS and WNH, other risk factors such as low education and hypertension appear to be important only for WNH. Risk factors for AD reported or suggested previously that were not confirmed by this study include smoking and head trauma with loss of consciousness.