title: Glycated hemoglobin levels and intellectual activity in an aged population.
abstract: OBJECTIVE
  To examine the association between glycated hemoglobin (GHb) and aspects of daily activities in an elderly population.
  
  
  METHODS
  Cross-sectional population-based survey.
  
  
  METHODS
  Nangai village, an agricultural community with a population of about 5,000 located in Akita prefecture in the north of Japan.
  
  
  METHODS
  Nine hundred thirty-five people aged 65 and older.
  
  
  METHODS
  GHb percentages, self-reported measures of activities of daily living (ADLs) and instrumental activities of daily living (IADLs), intellectual activity (IA), and social role (SR).
  
  
  RESULTS
  An exploratory analysis indicated that nondiabetic subjects in the lowest tertile of GHb tend to have lower IA than those in the middle tertile, if they were aged 70 and older. No consistent association appeared between GHb and ADLs, IADLs, or SR. Linear and logistic regression analyses, controlling for other risk factors, indicated significantly lower IA scores in the low and high GHb tertiles (P<.001 and P=.04, respectively) than in the middle in nondiabetic subjects aged 70 and older and without stroke history or IADL impairments. The value of GHb related to the maximal IA score was 5.0% to 5.2% as the middle tertile; or 5.2%, assuming a logistic regression model including a squared term with GHb as a continuous variable. A similar relationship was observed in the whole nondiabetic sample aged 70 and older but not in the younger counterpart.
  
  
  CONCLUSIONS
  There is an inverted U-shaped relationship between GHb and intellectual activity in older people without diabetes mellitus. One possible interpretation is that suboptimal blood glucose could contribute to intellectual inactivity in older people.
authors.affiliation: Community Health Research Group, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan. amano@tmig.or.jp
authors.forename: Hidenori
authors.initials: H
authors.lastname: Amano
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Watanabe
authors.forename: Shu
authors.initials: S
authors.lastname: Kumagai
authors.forename: Harumi
authors.initials: H
authors.lastname: Yukawa
authors.forename: Takao
authors.initials: T
authors.lastname: Suzuki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shibata
mesh_terms: D000203:Activities of Daily Living; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007564:Japan; D008297:Male; D015999:Multivariate Analysis; D012044:Regression Analysis; D017678:Sex Distribution
chemical_list: D006442:Glycated Hemoglobin