A randomized-controlled, double-blind study of the impact of selenium supplementation on thyroid autoimmunity and inflammation with focus on the GPx1 genotypes

J Endocrinol Invest. 2015 Oct;38(10):1065-74. doi: 10.1007/s40618-015-0285-8. Epub 2015 Apr 17.

Abstract

Purpose: To analyze the impact of selenium supplementation on serum antiTPO levels and thyroid echogenicity in patients with CAT, evaluating the response in subgroups with different GPx1 genotypes.

Methods: CAT patients (n = 55) with positive antiTPO were randomized to selenomethionine (SeMet) 200 μg daily (n = 28) or placebo (n = 27) for 3 months. Assessments included GPx1 genotyping at baseline and serum levels of plasma selenium, erythrocyte GPx1 activity, antiTPO and thyroid echogenicity at baseline, and 3 and 6 months.

Results: In the SeMet group, the increase in plasma levels of selenium and erythrocyte GPx1 activity was similar among patients with different GPx1 genotypes. In the overall cohort, patients randomized to SeMet showed a 5 % decrease in antiTPO levels at 3 months (p = non-significant) and 20 % at 6 months (p < 0.001 versus 3 months). In contrast, patients in the placebo group did not show significant changes in antiTPO levels at any time point. Subgroup analysis showed that patients with different GPx1 genotypes presented comparable responses in antiTPO levels and echogenicity index to SeMet.

Conclusions: Selenium supplementation decreased serum antiTPO levels in CAT patients, with similar response among patients with different GPx1 genotypes.

Keywords: Autoimmunity; Genetic; Glutathione peroxidase GPx1; Polymorphism; Selenium; Thyroid gland.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Autoimmunity / drug effects*
  • Dietary Supplements*
  • Double-Blind Method
  • Female
  • Genotype
  • Glutathione Peroxidase / genetics*
  • Glutathione Peroxidase GPX1
  • Humans
  • Inflammation / drug therapy
  • Inflammation / genetics
  • Inflammation / immunology
  • Iodide Peroxidase / immunology*
  • Male
  • Middle Aged
  • Selenomethionine / administration & dosage
  • Selenomethionine / therapeutic use*
  • Thyroid Gland / drug effects*
  • Thyroid Gland / immunology
  • Thyroiditis, Autoimmune / drug therapy*
  • Thyroiditis, Autoimmune / genetics
  • Thyroiditis, Autoimmune / immunology
  • Treatment Outcome
  • Young Adult

Substances

  • Selenomethionine
  • Iodide Peroxidase
  • Glutathione Peroxidase
  • Glutathione Peroxidase GPX1
  • GPX1 protein, human