title: Glycated haemoglobin (HbA1c), diabetes and trajectories of change in episodic memory performance.
abstract: As the ageing population grows, it is important to identify strategies to moderate cognitive ageing.
  
  
  
  We examined glycated haemoglobin (HbA1c) and diabetes in relation to level and change in episodic memory in older adults with and without diabetes.
  
  
  
  Data from 4419 older adults with (n=950) and without (n=3469) diabetes participating in a nationally representative longitudinal panel study (the Health and Retirement Study) were examined. Average baseline age was 72.66 years and 58% were women. HbA1c was measured in 2006 and episodic memory was measured using immediate and delayed list recall over 4 biennial waves between 2006 and 2012. Growth curve models were used to assess trajectories of episodic memory change.
  
  
  
  In growth curve models adjusted for age, sex, education, race, depressive symptoms and waist circumference, higher HbA1c levels and having diabetes were associated with poorer baseline episodic memory (p=0.036 and <0.001, respectively) and greater episodic memory decline (p=0.006 and 0.004, respectively). The effect of HbA1c on episodic memory decline was smaller than the effect of age. The results were stronger for women than men and were not modified by age or race. When the main analyses were estimated for those with and without diabetes separately, HbA1c was significantly linked to change in episodic memory only among those with diabetes.
  
  
  
  Higher HbA1c and diabetes were both associated with declines in episodic memory, with this relationship further exacerbated by having diabetes and elevated HbA1c. HbA1c appeared more important for episodic memory performance among women than men.
authors.affiliation: School of Aging Studies, University of South Florida, Tampa, Florida, USA.
authors.forename: Colleen
authors.initials: C
authors.lastname: Pappas
authors.affiliation: School of Aging Studies, University of South Florida, Tampa, Florida, USA.|International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic.
authors.forename: Ross
authors.initials: R
authors.lastname: Andel
authors.affiliation: Department of Psychology, Arizona State University, Tempe, Arizona, USA.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Infurna
authors.affiliation: Department of Psychology, St. Ambrose University, Davenport, Iowa, USA.|Center for Aging, St. Ambrose University, Davenport, Iowa, USA.
authors.forename: Shyam
authors.initials: S
authors.lastname: Seetharaman
mesh_terms: D000368:Aged; D000066492:Cognitive Aging; D003710:Demography; D003920:Diabetes Mellitus / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D061212:Memory, Episodic; D012307:Risk Factors; D012737:Sex Factors; D014481:United States
chemical_list: D006442:Glycated Hemoglobin
keywords: AGEING; COGNITION; DIABETES