Racial Differences in the Association Between Apolipoprotein E Risk Alleles and Overall and Total Cardiovascular Mortality Over 18 Years.

Objectives To examine the difference in the association between apolipoprotein ( APO)E allele and overall and cardiovascular mortality between African Americans ( AAs) and European Americans ( EAs). Design Longitudinal, cohort study of 18 years. Setting Biracial urban US population sample. Participants 4,917, 68% AA and 32% EA. Measurements APOE genotype and mortality based on National Death Index. Results A higher proportion of AAs than of EAs had an APOE ε2 allele ( ε2 ε2/ ε2 ε3/ ε2 ε4; 22% vs 13%) and an APOE ε4 allele ( ε3 ε4/ ε4 ε4; 33% vs 24%). After adjusting for known risk factors, the risk of mortality was 19% less with the APOE ε2 allele (hazard ratio ( HR) = 0.81, 95% confidence interval ( CI) = 0.76-0.87), and the risk of cardiovascular mortality was 35% less ( HR = 0.65, 95% CI = 0.58-0.76) than with the ε3 ε3 allele. The risk of mortality was 10% greater with the APOE ε4 allele ( HR = 1.10, 95% CI = 1.04-1.16), and the risk of cardiovascular mortality was 20% greater ( HR = 1.20, 95% CI = 1.07-1.29) than with the ε3 ε3 allele. No difference in the association between APOE allele and mortality was observed between AAs and EAs. Conclusion The APOE ε4 allele increased the risk of overall and cardiovascular mortality, whereas the APOE ε2 allele decreased the risk of overall and cardiovascular mortality. There was no racial difference in the association between these alleles and mortality. [ABSTRACT FROM AUTHOR]