title: Thyroid function and prevalent and incident metabolic syndrome in older adults: the Health, Ageing and Body Composition Study.
abstract: OBJECTIVE
  Both subclinical hypothyroidism and the metabolic syndrome have been associated with increased risk of coronary heart disease events. It is unknown whether the prevalence and incidence of metabolic syndrome is higher as TSH levels increase, or in individuals with subclinical hypothyroidism. We sought to determine the association between thyroid function and the prevalence and incidence of the metabolic syndrome in a cohort of older adults.
  
  
  METHODS
  Data were analysed from the Health, Ageing and Body Composition Study, a prospective cohort of 3075 community-dwelling US adults.
  
  
  METHODS
  Two thousand one hundred and nineteen participants with measured TSH and data on metabolic syndrome components were included in the analysis.
  
  
  METHODS
  TSH was measured by immunoassay. Metabolic syndrome was defined per revised ATP III criteria.
  
  
  RESULTS
  At baseline, 684 participants met criteria for metabolic syndrome. At 6-year follow-up, incident metabolic syndrome developed in 239 individuals. In fully adjusted models, each unit increase in TSH was associated with a 3% increase in the odds of prevalent metabolic syndrome (OR, 1.03; 95% CI, 1.01-1.06; P = 0.02), and the association was stronger for TSH within the normal range (OR, 1.16; 95% CI, 1.03-1.30; P = 0.02). Subclinical hypothyroidism with a TSH > 10 mIU/l was significantly associated with increased odds of prevalent metabolic syndrome (OR, 2.3; 95% CI, 1.0-5.0; P = 0.04); the odds of incident MetS was similar (OR 2.2), but the confidence interval was wide (0.6-7.5).
  
  
  CONCLUSIONS
  Higher TSH levels and subclinical hypothyroidism with a TSH > 10 mIU/l are associated with increased odds of prevalent but not incident metabolic syndrome.
authors.affiliation: Department of Medicine, University of California, San Francisco, San Francisco, CA, USA. avantika.waring@ucsf.edu
authors.forename: Avantika C
authors.initials: AC
authors.lastname: Waring
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rodondi
authors.forename: Stephanie
authors.initials: S
authors.lastname: Harrison
authors.forename: Alka M
authors.initials: AM
authors.lastname: Kanaya
authors.forename: Eleanor M
authors.initials: EM
authors.lastname: Simonsick
authors.forename: Iva
authors.initials: I
authors.lastname: Miljkovic
authors.forename: Suzanne
authors.initials: S
authors.lastname: Satterfield
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Bauer
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000453:epidemiology*; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000378:metabolism* / Q000502:physiology; D013972:Thyrotropin / Q000097:blood
chemical_list: D013972:Thyrotropin