Oxysterol species generated by auto-oxidation in subclinical hypothyroidism

ÜNLÜTÜRK U., Savas M., Oguz S. H., Samadi A., FIRLATAN B., YÜCE D., ...More

CLINICAL BIOCHEMISTRY, vol.93, pp.73-79, 2021 (SCI-Expanded, Scopus) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 93
  • Publication Date: 2021
  • Doi Number: 10.1016/j.clinbiochem.2021.04.007
  • Journal Name: CLINICAL BIOCHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, CAB Abstracts, EMBASE, MEDLINE, Veterinary Science Database
  • Page Numbers: pp.73-79
  • Keywords: Oxysterol, Subclinical hypothyroidism, Autoimmune thyroiditis, Atherosclerosis, Oxidative stress, Tandem mass spectrometry, LOW-DENSITY-LIPOPROTEIN, CORONARY-HEART-DISEASE, THYROID-DYSFUNCTION, OXIDATIVE STRESS, LIPID-PEROXIDATION, ANTIOXIDANT STATUS, IN-VITRO, 7-KETOCHOLESTEROL, PLASMA, RISK
  • Hacettepe University Affiliated: Yes

Abstract

Background: Auto-oxidized oxysterols are implicated in the pathogenesis of various chronic diseases. Their concentrations are indicators of oxidative stress in vivo and associated with atherosclerosis. Subclinical hypothyroidism is related with cardiac diseases and oxidative stress, but the exact mechanisms underlying these associations are not clear yet.& nbsp; Objective: To investigate the auto-oxidized oxysterols, 7-ketocholesterol (7-KC) and cholestane-313,5a,613-triol (chol-triol), in patients with subclinical hypothyroidism, as well as to evaluate the impact of restoring euthyroidism on oxysterol concentrations.& nbsp; Methods: In this prospective observational study, 64 patients with newly diagnosed autoimmune thyroiditis (41 with subclinical hypothyroidism and 23 euthyroidism), and 45 healthy controls were enrolled. Age, gender, and body mass index were matched among patient groups and healthy controls. Anthropometric measurements were obtained and fasting plasma 7-ketocholesterol and cholestane-313,5a,613-triol concentrations were measured by using liquid chromatography coupled with tandem mass spectrometry. Levothyroxine was then administered to all patients with subclinical-hypothyroidism. After three months, measurements of the oxysterols and serum cholesterols from the patients who have become euthyroid were repeated.& nbsp; Results: Concentrations of 7-ketocholesterol and cholestane-313,5a,613-triol were significantly higher in patients with subclinical-hypothyroidism when compared to both euthyroid patients and healthy controls (p < 0.001 for both oxysterols). After restoration of euthyroidism, concentrations of 7-ketocholesterol and cholestane-313,5a,613triol decreased significantly and reached similar concentrations observed in healthy controls (p < 0.001 for both oxysterols). Conclusions: Auto-oxidized oxysterol species are higher in patients with mild thyroid dysfunction, and supported the rationale for treating subclinical-hypothyroidism.