title: Genetic and lifestyle predictors of 15-year longitudinal change in episodic memory.
abstract: OBJECTIVE
  To reveal distinct longitudinal trajectories in episodic memory over 15 years and to identify demographic, lifestyle, health-related, and genetic predictors of stability or decline.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  The Betula Project, Umeå, Sweden.
  
  
  METHODS
  One thousand nine hundred fifty-four healthy participants aged 35 to 85 at baseline.
  
  
  METHODS
  Memory was assessed according to validated episodic memory tasks in participants from a large population-based sample. Data were analyzed using a random-effects pattern-mixture model that considered the effect of attrition over two to four longitudinal sessions. Logistic regression was used to determine significant predictors of stability or decline relative to average change in episodic memory.
  
  
  RESULTS
  Of 1,558 participants with two or more test sessions, 18% were classified as maintainers and 13% as decliners, and 68% showed age-typical average change. More educated and more physically active participants, women, and those living with someone were more likely to be classified as maintainers, as were carriers of the met allele of the catechol-O-methyltransferase gene. Less educated participants, those not active in the labor force, and men were more likely to be classified as decliners, and the apolipoprotein E ~4 allele was more frequent in decliners.
  
  
  CONCLUSIONS
  Quantitative, attrition-corrected assessment of longitudinal changes in memory can reveal substantial heterogeneity in aging trajectories, and genetic and lifestyle factors predict such heterogeneity.
authors.affiliation: Department of Statistics, Umeå School of Business and Economics, Umeå University, Umeå, Sweden. maria.josefsson@stat.umu.se
authors.forename: Maria
authors.initials: M
authors.lastname: Josefsson
authors.forename: Xavier
authors.initials: X
authors.lastname: de Luna
authors.forename: Sara
authors.initials: S
authors.lastname: Pudas
authors.forename: Lars-Göran
authors.initials: LG
authors.lastname: Nilsson
authors.forename: Lars
authors.initials: L
authors.lastname: Nyberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics*; D000483:Alleles; D053327:Apolipoprotein E4 / Q000235:genetics; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics; D002394:Catechol O-Methyltransferase / Q000235:genetics; D003071:Cognition; D004522:Educational Status; D005260:Female; D006579:Heterozygote; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D061212:Memory, Episodic; D008875:Middle Aged; D010750:Phosphoproteins / Q000235:genetics
chemical_list: D053327:Apolipoprotein E4; D019208:Brain-Derived Neurotrophic Factor; D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins; C513637:WWC1 protein, human; D002394:Catechol O-Methyltransferase