title: Thyroid function abnormalities and cognitive impairment in elderly people: results of the Invecchiare in Chianti study.
abstract: OBJECTIVE
  To investigate thyroid function testing abnormalities in older persons and to explore the relationship between thyroid dysfunction and cognition.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  Community-based.
  
  
  METHODS
  One thousand one hundred seventy-one men and women aged 23 to 102.
  
  
  METHODS
  Thyroid function was evaluated by measuring plasma concentrations of thyrotropin (TSH), free thyroxine (FT4), and free triiodothyronine (FT3). Cognition was evaluated using the Mini-Mental State Examination (MMSE). Prevalence of overt and subclinical thyroid dysfunction was evaluated in different age groups (<65 vs > or =65). Age trends in TSH, FT4, and FT3 were examined in euthyroid participants. The cross-sectional association between thyroid dysfunction and MMSE score was evaluated adjusting for confounders.
  
  
  RESULTS
  Subclinical hypothyroidism and subclinical hyperthyroidism were more prevalent in older than in younger participants (subclinical hypothyroidism, 3.5% vs 0.4%, P<.03; subclinical hyperthyroidism, 7.8% vs 1.9%, P<.002). In euthyroid participants, TSH and FT3 declined with age, whereas FT4 increased. Older participants with subclinical hyperthyroidism had lower MMSE scores than euthyroid subjects (22.61+/-6.88 vs 24.72+/-4.52, P<.03). In adjusted analyses, participants with subclinical hyperthyroidism were significantly more likely to have cognitive dysfunction (hazard rate=2.26, P=.003).
  
  
  CONCLUSIONS
  Subtle age-related changes in FT3, FT4, and TSH occur in individuals who remain euthyroid. Subclinical hyperthyroidism is the most prevalent thyroid dysfunction in Italian older persons and is associated with cognitive impairment.
authors.affiliation: Department of Geriatrics, Endocrine Unit, University of Parma, Italy. ceresini@unipr.it
authors.forename: Graziano
authors.initials: G
authors.lastname: Ceresini
authors.forename: Fulvio
authors.initials: F
authors.lastname: Lauretani
authors.forename: Marcello
authors.initials: M
authors.lastname: Maggio
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Ceda
authors.forename: Simonetta
authors.initials: S
authors.lastname: Morganti
authors.forename: Elisa
authors.initials: E
authors.lastname: Usberti
authors.forename: Carlo
authors.initials: C
authors.lastname: Chezzi
authors.forename: Rita
authors.initials: R
authors.lastname: Valcavi
authors.forename: Stefania
authors.initials: S
authors.lastname: Bandinelli
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: Anne R
authors.initials: AR
authors.lastname: Cappola
authors.forename: Giorgio
authors.initials: G
authors.lastname: Valenti
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000150:complications*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood* / Q000150:complications; D007037:Hypothyroidism / Q000097:blood* / Q000150:complications; D007558:Italy; D008297:Male; D008875:Middle Aged; D013960:Thyroid Function Tests; D055815:Young Adult