Statin use and the risk of Alzheimer's disease: The MIRAGE Study

Background: The aim of this study was to examine the association between statin use before the onset of Alzheimer's disease (AD) symptoms and risk of having AD, and to explore the potential impact of APOE genotype and race on this association. Methods: Data were collected through standardized, validated questionnaires from 895 subjects with probable or definite AD by research criteria, and 1,483 of their nondemented relatives in this family-based, case-control study of AD patients and their relatives enrolled at 15 research centers from 1996 through 2002. To minimize temporal and prescription biases, exposure to statin use within each family was ignored in the one year before the first appearance of AD symptoms in that family's affected member. Associations were estimated using generalized estimating equations for a logistic model, adjusting for age, sex, race, education, history of heart disease, stroke, diabetes, smoking and APOE genotype. Results: Statin use was associated with lowered odds of having AD (adjusted odds ratio [OR], 0.61; 95% confidence interval [CI], 0.38 to 0.98). Nonstatin cholesterol-lowering medications were not associated significantly with lowered odds of having had AD (adjusted OR, 1.7; 95% CI, 0.61 to 5.0). Conclusions: Statin medications were associated with lowered risk of AD in this population. Neither African-American race, nor the presence of the APOE ε{lunate}4 allele modified the statin-AD association.