title: Fatigue in patients with coronary artery disease: association with thyroid axis hormones and cortisol.
abstract: OBJECTIVE
  In people with coronary artery disease, the association between endocrine measures and fatigue is not well understood. We evaluated possible associations of fatigue and exercise capacity with function of adrenal axis and thyroid axis.
  
  
  METHODS
  Sixty-five men and 18 women (mean age 55 years) attending a rehabilitation program were examined using the Multidimensional Fatigue Inventory, Dutch Exertion Fatigue Scale, and the Hospital Anxiety and Depression Scale. Exercise capacity was measured using a bicycle ergometer procedure. Serum concentrations of free triiodothyronine (T₃), free thyroxine (T₄), morning cortisol, afternoon cortisol, and change in cortisol concentrations (ΔCortisol) were measured.
  
  
  RESULTS
  In univariate regression analysis, lower free T₄ concentrations were associated with general and exertion fatigue, lower free T₃ concentrations were associated with general and physical fatigue, and lower ΔCortisol was associated with mental fatigue. After adjusting for age, sex, body mass index, hypertension, previous myocardial infarction, heart failure, diabetes, New York Heart Association functional class, depressive symptoms, and anxiety symptoms, lower free T3 concentrations remained associated with physical fatigue (β = -.224, p = .03); lower free T₄ concentrations, with exertion fatigue (β = -.219, p = .03); and lower morning cortisol and lower ΔCortisol concentrations, with mental fatigue (β = -.193 [p = .03] and β = -.180 [p =.04], respectively). Exercise capacity was not associated with endocrine factors.
  
  
  CONCLUSIONS
  In coronary artery disease patients, increased thyroid hormone concentrations are associated with decreased physical fatigue and decreased exertion fatigue, and increased cortisol concentrations with decreased mental fatigue. Exercise capacity is not associated with endocrine factors.
authors.affiliation: Behavioral Medicine Institute, Lithuanian University of Health Sciences, Palanga, Lithuania. a.bunevicius@yahoo.com
authors.forename: Adomas
authors.initials: A
authors.lastname: Bunevicius
authors.forename: Vilte
authors.initials: V
authors.lastname: Gintauskiene
authors.forename: Aurelija
authors.initials: A
authors.lastname: Podlipskyte
authors.forename: Remigijus
authors.initials: R
authors.lastname: Zaliunas
authors.forename: Julija
authors.initials: J
authors.lastname: Brozaitiene
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Prange
authors.forename: Robertas
authors.initials: R
authors.lastname: Bunevicius
mesh_terms: D000311:Adrenal Glands / Q000503:physiopathology*; D003324:Coronary Artery Disease / Q000150:complications / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005080:Exercise Test; D017079:Exercise Tolerance; D005221:Fatigue / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D005222:Mental Fatigue / Q000150:complications / Q000503:physiopathology; D008875:Middle Aged; D012044:Regression Analysis; D013961:Thyroid Gland / Q000503:physiopathology*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
chemical_list: D014284:Triiodothyronine; D013974:Thyroxine; D006854:Hydrocortisone