title: Apolipoprotein E ε2 and functional decline in amnestic mild cognitive impairment and Alzheimer disease.
abstract: BACKGROUND
  Recent work has demonstrated the potentially protective effects of the apolipoprotein E (APOE) ε2 allele on cognitive functioning in individuals at risk for developing Alzheimer disease. However, little is known regarding the effect of ε2 genotype on rate of change in daily functioning over time. The aim of the current study was to examine the relationship between APOE genotype and change over time in ability to perform daily activities.
  
  
  METHODS
  We examined the relationship between APOE genotype and change in the ability to perform activities of daily living at 12- and 24-month intervals in 225 healthy comparison subjects, 381 individuals with amnestic mild cognitive impairment, and 189 individuals with Alzheimer disease who were enrolled in the Alzheimer's Disease Neuroimaging Initiative study. Neuropsychological measures were also collected at each follow-up.
  
  
  RESULTS
  Overall, individuals with at least one APOE-ε2 allele showed less functional decline over time and better performance on neuropsychological measures than those without an ε2 allele, even after controlling for potential confounders. When diagnostic groups were examined individually, presence of the ε2 allele continued to be associated with slower functional decline, although the relationship was no longer statistically significant in most cases, likely due to reduced statistical power.
  
  
  CONCLUSIONS
  Our findings suggest that the APOE-ε2 allele provides a buffer against significant changes in daily functioning over time and is associated with better neuropsychological performance across a number of measures.
authors.affiliation: Warren Alpert Medical School of Brown University and Rhode Island Hospital, Providence, RI 02903, USA. abonnerjackson@lifespan.org
authors.forename: Aaron
authors.initials: A
authors.lastname: Bonner-Jackson
authors.forename: Ozioma
authors.initials: O
authors.lastname: Okonkwo
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Tremont
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D000544:Alzheimer Disease / Q000235:genetics* / Q000523:psychology*; D053329:Apolipoprotein E2 / Q000235:genetics*; D060825:Cognitive Dysfunction / Q000235:genetics* / Q000523:psychology*; D018450:Disease Progression; D005260:Female; D005838:Genotype; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data
chemical_list: D053329:Apolipoprotein E2