title: Serum TSH related to measures of body mass: longitudinal data from the HUNT Study, Norway.
abstract: OBJECTIVE
  Thyroid function and body mass are related, but the causal relationship remains unclear. Our objective was to investigate the longitudinal relationship between thyroid stimulating hormone (TSH) and body mass measures [body weight, body mass index (BMI), waist circumference (WC) and waist-hip-ratio (WHR)].
  
  
  METHODS
  We used data from two waves of a population-based study: HUNT 2 (1995-1997) and 3 (2006-2008). Average follow-up time was 10·5 years. Multivariable general linear and logistic regression models were used to assess the relation between TSH and the body mass measures.
  
  
  METHODS
  In total 9954 women and 5066 men without self-reported thyroid disease and TSH within the reference range (0·5-3·5 mU/l) at baseline and <10 mU/l at follow-up.
  
  
  RESULTS
  For each mU/l increase in TSH among women, weight increased 0·9 kg (95% CI 0·8, 1·1), BMI 0·3 kg/m(2) (95% CI 0·3, 0·4) and WC 0·6 cm (95% CI 0·3, 0·8). In men, the corresponding figures were 0·8 kg (95% CI 0·5, 1·0), 0·2 kg/m(2) (95% CI 0·2, 0·3) and 0·5 cm (95% CI 0·2, 0·8). In line with this, a weight gain of more than 5 kg was associated with a TSH increase of 0·08 mU/l (95% CI 0·06, 0·11) in women and 0·15 mU/l (95% CI 0·12, 0·18) in men. Women who lost more than 5 kg decreased their TSH by 0·12 mU/l (95% CI 0·09, 0·16) and men by 0·03 mU/l (95% CI -0.02, 0·09).
  
  
  CONCLUSIONS
  Weight gain is accompanied by increasing TSH, and weight loss in women is related to decreasing TSH.
authors.affiliation: Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. anders.svare@hnt.no
authors.forename: Anders
authors.initials: A
authors.lastname: Svare
authors.forename: Tom I L
authors.initials: TI
authors.lastname: Nilsen
authors.forename: Trine
authors.initials: T
authors.lastname: Bjøro
authors.forename: Bjørn O
authors.initials: BO
authors.lastname: Asvold
authors.forename: Arnulf
authors.initials: A
authors.lastname: Langhammer
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009664:Norway; D011795:Surveys and Questionnaires; D013959:Thyroid Diseases / Q000097:blood / Q000503:physiopathology; D013972:Thyrotropin / Q000097:blood*; D055105:Waist Circumference; D049629:Waist-Hip Ratio; D015430:Weight Gain; D015431:Weight Loss; D055815:Young Adult
chemical_list: D013972:Thyrotropin