title: Predicting cognitive ability in ageing cohorts using Type 2 diabetes genetic risk.
abstract: OBJECTIVE
  To investigate whether there is overlap in the genetic determinants of Type 2 diabetes and cognitive ageing by testing whether a genetic risk score for Type 2 diabetes can predict variation in cognitive function in older people without dementia.
  
  
  METHODS
  Type 2 diabetes genetic risk scores were estimated using various single nucleotide polymorphism significance inclusion criteria from an initial genome-wide association study, the largest in Type 2 diabetes to date. Scores were available for 2775-3057 individuals, depending on the cognitive trait.
  
  
  RESULTS
  Type 2 diabetes genetic risk was associated with self-reported diabetes mellitus. Across varying single nucleotide polymorphism-inclusion levels, a significant association between Type 2 diabetes genetic risk and change in general cognitive function was found (median r = 0.04); however, this was such that higher Type 2 diabetes genetic risk related to higher cognitive scores.
  
  
  CONCLUSIONS
  To investigate more fully the source of the often observed comorbidity between Type 2 diabetes and cognitive impairment, one direction for future research will be to use cognitive ability polygenic risk scores to predict Type 2 diabetes in line with the reverse causation hypothesis that people with lower pre-morbid cognitive ability are more likely to develop Type 2 diabetes.
authors.affiliation: Department of Psychology, The University of Edinburgh, Edinburgh, UK; Centre for Cognitive Ageing and Cognitive Epidemiology, The University of Edinburgh, Edinburgh, UK.
authors.forename: M
authors.initials: M
authors.lastname: Luciano
authors.forename: R
authors.initials: R
authors.lastname: Mõttus
authors.forename: S E
authors.initials: SE
authors.lastname: Harris
authors.forename: G
authors.initials: G
authors.lastname: Davies
authors.forename: A
authors.initials: A
authors.lastname: Payton
authors.forename: W E R
authors.initials: WE
authors.lastname: Ollier
authors.forename: M A
authors.initials: MA
authors.lastname: Horan
authors.forename: J M
authors.initials: JM
authors.lastname: Starr
authors.forename: D J
authors.initials: DJ
authors.lastname: Porteous
authors.forename: N
authors.initials: N
authors.lastname: Pendleton
authors.forename: I J
authors.initials: IJ
authors.lastname: Deary
mesh_terms: D000328:Adult; D000368:Aged; D003072:Cognition Disorders / Q000235:genetics*; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics* / Q000523:psychology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D055106:Genome-Wide Association Study; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors