title: Cholesterol, APOE genotype, and Alzheimer disease: an epidemiologic study of Nigerian Yoruba.
abstract: OBJECTIVE
  To examine the relationship between cholesterol and other lipids, APOE genotype, and risk of Alzheimer disease (AD) in a population-based study of elderly Yoruba living in Ibadan, Nigeria.
  
  
  METHODS
  Blood samples and clinical data were collected from Yoruba study participants aged 70 years and older (N = 1,075) as part of the Indianapolis-Ibadan Dementia Project, a longitudinal epidemiologic study of AD. Cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglyceride levels were measured in fasting blood samples. DNA was extracted and APOE was genotyped. Diagnoses of AD were made by consensus using National Institute of Neurologic Disorders/Stroke-Alzheimer's Disease and Related Disorders Association criteria.
  
  
  RESULTS
  Logistic regression models showed interaction after adjusting for age and gender between APOE-epsilon4 genotype and biomarkers in the risk of AD cholesterol*genotype (p = 0.022), LDL*genotype (p= 0.018), and triglyceride*genotype (p = 0.036). Increasing levels of cholesterol and LDL were associated with increased risk of AD in individuals without the APOE-epsilon4 allele, but not in those with APOE-epsilon4. There was no significant association between levels of triglycerides and AD risk in those without APOE-epsilon4.
  
  
  CONCLUSIONS
  There was a significant interaction between cholesterol, APOE-epsilon4, and the risk of Alzheimer disease (AD) in the Yoruba, a population that has lower cholesterol levels and lower incidence rates of AD compared to African Americans. APOE status needs to be considered when assessing the relationship between lipid levels and AD risk in population studies.
authors.affiliation: Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN 46202, USA. khall@iupui.edu
authors.forename: K
authors.initials: K
authors.lastname: Hall
authors.forename: J
authors.initials: J
authors.lastname: Murrell
authors.forename: A
authors.initials: A
authors.lastname: Ogunniyi
authors.forename: M
authors.initials: M
authors.lastname: Deeg
authors.forename: O
authors.initials: O
authors.lastname: Baiyewu
authors.forename: S
authors.initials: S
authors.lastname: Gao
authors.forename: O
authors.initials: O
authors.lastname: Gureje
authors.forename: J
authors.initials: J
authors.lastname: Dickens
authors.forename: R
authors.initials: R
authors.lastname: Evans
authors.forename: V
authors.initials: V
authors.lastname: Smith-Gamble
authors.forename: F W
authors.initials: FW
authors.lastname: Unverzagt
authors.forename: J
authors.initials: J
authors.lastname: Shen
authors.forename: H
authors.initials: H
authors.lastname: Hendrie
mesh_terms: D000368:Aged; D000483:Alleles; D000544:Alzheimer Disease / Q000097:blood* / Q000208:ethnology / Q000209:etiology* / Q000235:genetics; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics*; D044383:Black People / Q000235:genetics*; D002784:Cholesterol / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood; D004198:Disease Susceptibility; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D016015:Logistic Models; D008297:Male; D009549:Nigeria / Q000453:epidemiology; D001741:Black or African American
chemical_list: D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D008078:Cholesterol, LDL; D002784:Cholesterol