title: Self- or physician-reported diabetes, glycemia markers, and cognitive functioning in older adults in Germany.
abstract: OBJECTIVE
  To assess the association of different diabetes-related variables, including self- and physician-reported information, as well as biomarkers, with cognitive functioning in the elderly general population in Germany.
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  A total of 1,697 subjects with a mean ± standard deviation age of 74 ± 2.8 years were included. These were recruited from among the participants of an ongoing epidemiological study of the elderly general population in Saarland state and had been recruited 5 years earlier on the occasion of a health screening exam by their general practitioners.
  
  
  METHODS
  Cognitive functioning across six subdomains was assessed using the Cognitive Telephone Screening Instrument. Data on prevalent diabetes at baseline were obtained from the study participants and their general practitioners. Baseline fasting glucose was assessed as part of the screening exam, and baseline HbA1c was determined centrally by standardized methods.
  
  
  RESULTS
  The association of cognitive functioning with self-reported diabetes (N = 189) was more pronounced than with physician-reported diabetes (N = 280). HbA1c showed a nonlinear association with cognitive functioning, with a peak of cognitive performance in the central quintile of HbA1c. In the case of fasting glucose, lower cognitive functioning was only observed in the highest quintile. The estimates were robust in confounder-adjusted models, but attentuated when excluding subjects with baseline prevalent or follow-up incident diabetes.
  
  
  CONCLUSIONS
  Future studies of diabetes-related biomarkers and cognition should take possible nonlinearity of the relationships into account, as the strength of the associations otherwise might be underestimated.
authors.affiliation: Division C070 Clinical Epidemiology and Aging Research (LPB, HO, HM, BS, HB), German Cancer Research Center (DKFZ), Heidelberg, Germany. Electronic address: Lutz.Breitling@gmail.com.
authors.forename: Lutz P
authors.initials: LP
authors.lastname: Breitling
authors.affiliation: Division C070 Clinical Epidemiology and Aging Research (LPB, HO, HM, BS, HB), German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Hutson
authors.initials: H
authors.lastname: Olsen
authors.affiliation: Division C070 Clinical Epidemiology and Aging Research (LPB, HO, HM, BS, HB), German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Müller
authors.affiliation: Division C070 Clinical Epidemiology and Aging Research (LPB, HO, HM, BS, HB), German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Ben
authors.initials: B
authors.lastname: Schöttker
authors.affiliation: Department of Psychology, University of Geneva, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Kliegel
authors.affiliation: Division C070 Clinical Epidemiology and Aging Research (LPB, HO, HM, BS, HB), German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Brenner
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis*; D003071:Cognition; D003072:Cognition Disorders / Q000453:epidemiology / Q000209:etiology; D060825:Cognitive Dysfunction / Q000453:epidemiology / Q000209:etiology; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood / Q000453:epidemiology*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008297:Male; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: Fasting glucose; glycated hemoglobin; mild cognitive impairment