title: Thyroid status and functional and cognitive status at baseline and survival after 3 years of follow-up: the OCTABAIX study.
abstract: OBJECTIVE
  Subclinical thyroid disorders are common in older individuals. Health risks associated with subclinical hypothyroidism in older adults are unclear. The aim of the study is to evaluate whether thyroid status in elderly subjects correlates with physical and cognitive function at baseline and with 3-year mortality.
  
  
  METHODS
  A population-based, prospective cohort of the OCTABAIX study (307 inhabitants aged 85 years at baseline).
  
  
  METHODS
  Chronic drug prescription, functional status (Barthel and Lawton indices) and cognitive status according to the Spanish version of the Mini-Mental State Examination were recorded. Quality of life was assessed using the visual analogue scale of the quality of life test. Concentrations of TSH and thyroxine were measured. Participants were classified in accordance with clinical categories of thyroid function.
  
  
  RESULTS
  Twenty (6.5%) individuals had subclinical hypothyroidism and five (1.6%) had subclinical hyperthyroidism. Compared with euthyroid subjects (n=280; 91.8%), subclinical hypo- and hyperthyroidism subjects were not significantly associated with poor physical or cognitive function at baseline. Fifty-one (15.1%) subjects died during the 36 months of follow-up. TSH values and subclinical hypo- and hyperthyroidism were not associated with an increased overall mortality risk (hazard ratio (HR) 1.086, 95% CI 0.987-1.196 and HR 0.905, 95% CI 0.902-1.053 respectively).
  
  
  CONCLUSIONS
  This study does not support the association of TSH or thyroid disorders with physical or cognitive function at baseline or with 3-year mortality in the oldest old subjects.
authors.affiliation: Geriatric Unit, Internal Medicine Service, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, 08907 Llobregat, Barcelona, Spain.
authors.forename: Francesc
authors.initials: F
authors.lastname: Formiga
authors.forename: Assumpta
authors.initials: A
authors.lastname: Ferrer
authors.forename: Gloria
authors.initials: G
authors.lastname: Padros
authors.forename: Anna
authors.initials: A
authors.lastname: Contra
authors.forename: Xavier
authors.initials: X
authors.lastname: Corbella
authors.forename: Ramon
authors.initials: R
authors.lastname: Pujol
mesh_terms: D000369:Aged, 80 and over; D000375:Aging; D060825:Cognitive Dysfunction / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D015331:Cohort Studies; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D007037:Hypothyroidism / Q000097:blood / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D009026:Mortality; D015596:Nutrition Assessment; D011788:Quality of Life; D012720:Severity of Illness Index; D013030:Spain / Q000453:epidemiology; D016019:Survival Analysis; D013961:Thyroid Gland / Q000378:metabolism*; D013972:Thyrotropin / Q000097:blood / Q000378:metabolism*; D013974:Thyroxine / Q000097:blood / Q000378:metabolism
chemical_list: D013972:Thyrotropin; D013974:Thyroxine