Apolipoprotein E genotypes and the risk of Parkinson disease

We examined apolipoprotein E (ApoE) genotypes in relation to Parkinson's disease (PD) among 786 cases and 1537 controls, all non-Hispanic Caucasians. Odds ratios (ORO and 95% confidence intervals (CIs) were derived from multivariate logistic regression models, adjusting for year of birth, sex, smoking status, daily caffeine intake, and family history of PD. Compared with participants with ApoE epsilon 33, epsilon 4 carriers (epsilon 34/epsilon 44) had significantly lower odds for having PD (OR, 0.75; 95% Cl, 0.59-0.94; p = 0.01), whereas epsilon 2 carriers (epsilon 23/epsilon 22) did not (OR, 0.95; 95% CI, 0.73-1.24; p = 0.71). Subgroup analyses showed similar results. in addition, we conducted a meta-analysis which confirmed our primary findings (epsilon 34/epsilon 44 vs. epsilon 33: OR, 0.90; 95% CI, 0.81-0.99; p = 0.024 and epsilon 23/epsilon 22 vs. epsilon 33: OR, 1.10; 95% CI, 0.97-1.23; p = 0.13). in PD patients, the prevalence of dementia appeared to be higher among epsilon 4 carriers (compared with epsilon 33: OR, 1.59; 95% CI, 0.98-2.58; p = 0.06), but lower among epsilon 2 carriers (OR, 0.75; 95% CI, 0.40-1.42; p = 0.38), although neither test was statistically significant. Our study suggested that the ApoE epsilon 4 allele may be associated with a lower PD risk among non-Hispanic Caucasians. Published by Elsevier Inc.