title: Memory Resilience to Alzheimer's Genetic Risk: Sex Effects in Predictor Profiles.
abstract: OBJECTIVE
  Apolipoprotein E (APOE) ɛ4 and Clusterin (CLU) C alleles are risk factors for Alzheimer's disease (AD) and episodic memory (EM) decline. Memory resilience occurs when genetically at-risk adults perform at high and sustained levels. We investigated whether (a) memory resilience to AD genetic risk is predicted by biological and other risk markers and (b) the prediction profiles vary by sex and AD risk variant.
  
  
  METHODS
  Using a longitudinal sample of nondemented adults (n = 642, aged 53-95) we focused on memory resilience (over 9 years) to 2 AD risk variants (APOE, CLU). Growth mixture models classified resilience. Random forest analysis, stratified by sex, tested the predictive importance of 22 nongenetic risk factors from 5 domains (n = 24-112).
  
  
  RESULTS
  For both sexes, younger age, higher education, stronger grip, and everyday novel cognitive activity predicted memory resilience. For women, 9 factors from functional, health, mobility, and lifestyle domains were also predictive. For men, only fewer depressive symptoms was an additional important predictor. The prediction profiles were similar for APOE and CLU.
  
  
  CONCLUSIONS
  Although several factors predicted resilience in both sexes, a greater number applied only to women. Sex-specific mechanisms and intervention targets are implied.
authors.affiliation: Neuroscience and Mental Health Institute.
authors.forename: Kirstie L
authors.initials: KL
authors.lastname: McDermott
authors.affiliation: Neuroscience and Mental Health Institute.|Department of Psychology, University of Alberta, Edmonton, Canada.
authors.forename: G Peggy
authors.initials: GP
authors.lastname: McFall
authors.affiliation: Centre for Research on Ageing, Health and Wellbeing, The Australian National University, Canberra, Australia.
authors.forename: Shea J
authors.initials: SJ
authors.lastname: Andrews
authors.affiliation: Centre for Research on Ageing, Health and Wellbeing, The Australian National University, Canberra, Australia.
authors.forename: Kaarin J
authors.initials: KJ
authors.lastname: Anstey
authors.affiliation: Neuroscience and Mental Health Institute.|Department of Psychology, University of Alberta, Edmonton, Canada.
authors.forename: Roger A
authors.initials: RA
authors.lastname: Dixon
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000235:genetics* / Q000523:psychology*; D053327:Apolipoprotein E4 / Q000235:genetics; D051152:Clusterin / Q000235:genetics; D004522:Educational Status; D005260:Female; D006580:Genetic Carrier Screening; D005819:Genetic Markers; D018737:Hand Strength; D006801:Humans; D007206:Individuality; D008137:Longitudinal Studies; D008297:Male; D061212:Memory, Episodic; D008875:Middle Aged; D053580:Muscle Strength; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011594:Psychometrics; D055500:Resilience, Psychological; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D053327:Apolipoprotein E4; C495242:CLU protein, human; D051152:Clusterin; D005819:Genetic Markers
keywords: Alzheimer’s risk factors; Apolipoprotein E; Clusterin; Random forest analysis; Victoria Longitudinal Study