title: Serum thyroid-stimulating hormone levels are not associated with exercise capacity and lung function parameters in two population-based studies.
abstract: BACKGROUND
  Thyroid dysfunction has been described to be linked to a variety of cardiovascular morbidities. Through this pathway thyroid function might also be associated with cardiorespiratory function and exercise capacity. So far only few patient-studies with small study populations investigated the association between thyroid dysfunction and exercise capacity. Thus, the aim of our study was to investigate the association of serum thyroid-stimulating hormone (TSH) levels with lung function and cardiopulmonary exercise testing (CPET) in the general population.
  
  
  METHODS
  Data from the two independent cross-sectional population-based studies (Study of Health in Pomerania [SHIP] and SHIP-Trend-0) were pooled. SHIP was conducted between 2002 and 2006 and SHIP-Trend-0 between 2008 and 2012. Participants were randomly selected from population registries. In total, 4206 individuals with complete data were available for the present analysis. Thyroid function was defined based on serum TSH levels. Lung function was evaluated by forced expiratory volume in 1 s and forced vital capacity. CPET was based on symptom limited exercise tests on a bicycle in a sitting position according to a modified Jones protocol. Associations of serum TSH levels with lung function and CPET parameters were analysed by multivariable quantile regression adjusted for age, sex, height, weight, use of beta blockers, smoking status, and physical activity.
  
  
  RESULTS
  Serum TSH levels, used as continuously distributed variable and categorized according to the clinical cut-offs 0.3 and 3.0 mIU/L or according to quintiles, were not consistently associated with parameters of lung function or CPET.
  
  
  CONCLUSIONS
  Our results suggest that thyroid dysfunction is not associated with lung function and cardiopulmonary exercise capacity in the general population.
authors.affiliation: Institute for Community Medicine, Ernst Moritz Arndt University, Walther Rathenau Str, 48, D-17475 Greifswald, Germany. till.ittermann@uni-greifswald.de.
authors.forename: Till
authors.initials: T
authors.lastname: Ittermann
authors.forename: Sven
authors.initials: S
authors.lastname: Gläser
authors.forename: Ralf
authors.initials: R
authors.lastname: Ewert
authors.forename: Stephan
authors.initials: S
authors.lastname: Felix
authors.forename: Henry
authors.initials: H
authors.lastname: Völzke
authors.forename: Marcus
authors.initials: M
authors.lastname: Dörr
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold; D003430:Cross-Sectional Studies; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D013961:Thyroid Gland / Q000502:physiology*; D013972:Thyrotropin / Q000097:blood*; D014797:Vital Capacity
chemical_list: D013972:Thyrotropin; D010100:Oxygen