Affiliations: [a] Division of Biostatistics, Department of Medicine, Indiana University School of Medicine, IN USA | [b] Department of Psychiatry, Indiana University School of Medicine, IN USA | [c] Indiana University Center for Aging Research, Indiana University School of Medicine, IN, USA | [d] Department of Pathology Indiana University School of Medicine Indianapolis, IN, USA
Corresponding author: Kathleen A. Lane, Indiana University School of Medicine, Division of Biostatistics, 1050 Wishard Blvd. RG 4101, Indianapolis, IN 46202, USA. Tel.: +1 317 278 0510; Fax: +1 317 274 2678; E-mail: [email protected].
Abstract: The literature on the association between apolipoprotein E (ApoE) and mortality across ethnic and age groups has been inconsistent. No studies have looked at this association in developing countries. We used data from the Indianapolis-Ibadan Dementia study to examine this association between APOE and mortality in 354 African-Americans from Indianapolis and 968 Yoruba from Ibadan, Nigeria. Participants were followed up to 9.5 years for Indianapolis and 8.7 years for Ibadan. Subjects from both sites were divided into 2 groups based upon age at baseline. A Cox proportional hazards regression model adjusting for age at baseline, education, hypertension, smoking history and gender in addition to time-dependent covariates of cancer, diabetes, heart disease, stroke, and dementia was fit for each cohort and age group. Having ApoE ε4 alleles significantly increased mortality risk in Indianapolis subjects under age 75 (hazard ratio: 2.00; 95% CI: 1.19–3.35; p = 0.0089). No association was found in Indianapolis subjects 75 and older (hazard ratio: 0.71; 95% CI: 0.45–1.10; p = 0.1238), Ibadan subjects under 75 (hazard ratio: 1.04; 95% CI: 0.78 to 1.40; p = 0.7782), or Ibadan subjects over 75 (hazard ratio: 1.21; 95% CI: 0.83 to 1.75; p = 0.3274).
Keywords: apolipoprotein E, survival analysis, African-Americans