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 epsilon 2 allele (epsilon 2 epsilon 2/epsilon 2 epsilon 3/epsilon 2 epsilon 4; 22% vs 13%) and an APOE epsilon 4 allele (epsilon 3 epsilon 4/epsilon 4 epsilon 4; 33% vs 24%). After adjusting for known risk factors, the risk of mortality was 19% less with the APOE epsilon 2 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 epsilon 3 epsilon 3 allele. The risk of mortality was 10% greater with the APOE epsilon 4 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 epsilon 3 epsilon 3 allele. No difference in the association between APOE allele and mortality was observed between AAs and EAs. CONCLUSION: The APOE epsilon 4 allele increased the risk of overall and cardiovascular mortality, whereas the APOE epsilon 2 allele decreased the risk of overall and cardiovascular mortality. There was no racial difference in the association between these alleles and mortality.