title: Lower cognitive performance of older football players possessing apolipoprotein E epsilon4.
abstract: OBJECTIVE
  To determine whether the cognitive status of professional football players varies as a function of age and apolipoprotein E (APOE) genotype.
  
  
  METHODS
  Fifty-three active players underwent APOE and neuropsychological assessments. Players were grouped according to age (proxy indicator of high/low exposure to contact) and the presence/absence of at least one copy of the epsilon4 allele. Outcome measures were overall cognitive performance and scores in cognitive domains.
  
  
  RESULTS
  As a group, older players possessing APOE epsilon4 exhibited significantly lower cognitive test scores than did all other players studied, including non-epsilon4-possessing players and younger epsilon4-carriers. Measures of general cognitive functioning, information-processing speed and accuracy, and attention were related to poorer performance among the epsilon4-carrying players. In an analysis of variance model, the interaction between APOE genotype and age was significant (P = 0.004). As determined using linear regression, age accounted for 34% of the variance in the memory index among APOE epsilon4-possessing players but did not contribute significantly to variance among the non-epsilon4-possessing players. Older APOE epsilon4-carriers were significantly overrepresented among players whose scores indicated possible cognitive impairment, with the criterion of performing two or more standard deviations below the general normal values in a summary index of general cognitive functioning.
  
  
  CONCLUSIONS
  Older professional football players who possessed the APOE epsilon4 allele scored lower on cognitive tests than did players without this allele or less experienced players of any genotype. The cognitive status of professional athletes with repeated exposure to head trauma may therefore be influenced by age, inherited factors such as APOE genotype, and cumulative exposure to contact.
authors.affiliation: Department of Neurology and Neuroscience, New York Presbyterian Hospital-Weill Medical College of Cornell University, New York 10021, USA.
authors.forename: K C
authors.initials: KC
authors.lastname: Kutner
authors.forename: D M
authors.initials: DM
authors.lastname: Erlanger
authors.forename: J
authors.initials: J
authors.lastname: Tsai
authors.forename: B
authors.initials: B
authors.lastname: Jordan
authors.forename: N R
authors.initials: NR
authors.lastname: Relkin
mesh_terms: D000328:Adult; D000367:Age Factors; D000483:Alleles; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics*; D001265:Athletic Injuries / Q000175:diagnosis* / Q000235:genetics; D001925:Brain Damage, Chronic / Q000175:diagnosis / Q000235:genetics; D020208:Brain Injury, Chronic / Q000175:diagnosis* / Q000235:genetics; D003072:Cognition Disorders / Q000175:diagnosis* / Q000235:genetics; D005538:Football / Q000293:injuries*; D006580:Genetic Carrier Screening; D005838:Genotype; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D012307:Risk Factors
chemical_list: D053327:Apolipoprotein E4; D001057:Apolipoproteins E