title: Association between thyroid hormones, lipids and oxidative stress biomarkers in overt hypothyroidism.
abstract: BACKGROUND
  The aim of this study was to investigate the effect of hypothyroidism on lipid peroxidation and the antioxidant profile, as well as to evaluate the interaction between thyroid hormones and biomarkers of oxidative stress in patients with overt hypothyroidism. We also evaluated the influence of cholesterol concentrations on biomarkers of oxidative stress in these same patients.
  
  
  METHODS
  Total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and vitamin E were measured in 20 subjects with overt hypothyroidism (OH) and 20 controls.
  
  
  RESULTS
  TC, LDL cholesterol, triglycerides, TBARS, SOD, CAT, and vitamin E were significantly higher in the OH group. Significant correlation was observed for TSH and SOD, CAT, vitamin E and TBARS. Correlation was observed for triiodothyronine (T3) and SOD, CAT, vitamin E and TBARS. Significant correlation was also observed for free thyroxine and vitamin E and TBARS. However, correlation between T3 and CAT remained significant after controlling for TC concentrations.
  
  
  CONCLUSIONS
  Overt hypothyroidism is associated with an increase in oxidative stress, and hypercholesterolemia has a stronger influence on development of oxidative stress in hypothyroid conditions compared with thyroid hormones.
authors: Departamento de Fisiologia e Farmacologia, Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, RS, Brazil.
authors: Adriana
authors: A
authors: Santi
authors: Marta Maria Medeiros Frescura
authors: MM
authors: Duarte
authors: Rafael Noal
authors: RN
authors: Moresco
authors: Charlene
authors: C
authors: Menezes
authors: Margarete Dulce
authors: MD
authors: Bagatini
authors: Maria Rosa Chitolina
authors: MR
authors: Schetinger
authors: Vania Lucia
authors: VL
authors: Loro
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D002784:Cholesterol / Q000378:metabolism; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000378:metabolism*; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D013963:Thyroid Hormones / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D013963:Thyroid Hormones; D002784:Cholesterol