title: Apolipoprotein E gene and early age-related maculopathy: the Atherosclerosis Risk in Communities Study.
abstract: OBJECTIVE
  To examine the association between the apolipoprotein E (APOE) gene and early age-related maculopathy (ARM) in middle-aged persons.
  
  
  METHODS
  Population-based cross-sectional study.
  
  
  METHODS
  Participants from the Atherosclerosis Risk in Communities Study (n = 10139; age range, 49-73 years).
  
  
  METHODS
  Retinal photography was performed on 1 randomly selected eye, and grading for presence of ARM was carried out using a modification of the Wisconsin ARM Grading System. Early ARM was defined as the presence of either soft drusen alone, retinal pigment epithelial depigmentation alone, or a combination of soft drusen with increased retinal pigment and/or depigmentation. DNA extracted from blood samples of participants were analyzed for common allelic variants of the APOE gene (epsilon2, epsilon3, and epsilon4).
  
  
  METHODS
  Presence of early ARM on retinal photographs.
  
  
  RESULTS
  The prevalence of early ARM was similar in participants with different APOE genotypes: epsilon2/epsilon2 (5.9%), epsilon2/epsilon3 (5.2%), epsilon2/epsilon4 (3.2%), epsilon3/epsilon3 (5.2%), epsilon3/epsilon4 (4.9%), and epsilon4/epsilon4 (4.1%). After controlling for age, gender, race, cigarette smoking, and other factors, early ARM was not associated with APOE genotypes, with an odds ratio (OR) of 1.35 (95% confidence interval [CI], 0.54-3.38) for epsilon2/epsilon2 genotype, an OR of 1.06 (95% CI, 0.80-1.40) for epsilon2/epsilon3 genotype, an OR of 0.63 (95% CI, 0.32-1.24) for epsilon2/epsilon4 genotype, an OR of 0.99 (95% CI, 0.80-1.24) for epsilon3/epsilon4 genotype, and an OR of 0.88 (95% CI, 0.47-1.63) for epsilon4/epsilon4 genotype, as compared with epsilon3/epsilon3 genotype (reference). No associations were found for specific early ARM signs or in analyses stratified by age, gender, race, or cigarette smoking status.
  
  
  CONCLUSIONS
  These data provide no evidence of a strong association between the APOE gene and early ARM in middle-aged persons. This suggests that APOE is not likely a major determinant of the early stages of ARM in younger people. However, our study does not exclude the possibility of a weaker association or that APOE may influence only the development of late ARM in older populations, as reported in other studies.
authors.affiliation: Centre for Eye Research Australia, University of Melbourne, Melbourne, Victoria, Australia. twong@unimelb.edu.au
authors.forename: Tien Yin
authors.initials: TY
authors.lastname: Wong
authors.forename: Anoop
authors.initials: A
authors.lastname: Shankar
authors.forename: Ronald
authors.initials: R
authors.lastname: Klein
authors.forename: Molly S
authors.initials: MS
authors.lastname: Bray
authors.forename: David J
authors.initials: DJ
authors.lastname: Couper
authors.forename: Barbara E K
authors.initials: BE
authors.lastname: Klein
authors.forename: A Richey
authors.initials: AR
authors.lastname: Sharrett
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Folsom
mesh_terms: D000368:Aged; D001057:Apolipoproteins E / Q000235:genetics*; D003430:Cross-Sectional Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008268:Macular Degeneration / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010781:Photography; D015995:Prevalence; D012307:Risk Factors
chemical_list: D001057:Apolipoproteins E