Apolipoprotein E genotype and the association between C-reactive protein and postoperative delirium: Importance of gene-protein interactions

APOE ε4 carrier prevalence was 19%, and postoperative delirium occurred in 24%. The relationship between CRP and delirium incidence, severity, and duration differed by ε4 status. Among ε4 carriers, there was a strong relationship between high CRP (vs. low CRP) and delirium incidence (relative risk [95% confidence interval], 3.0 [1.4–6.7]); however, no significant association was observed among non-ε4 carriers (relative risk [95% CI], 1.2 [0.8–1.7]).