Effects of selenium and vitamin C on the serum level of antithyroid peroxidase antibody in patients with autoimmune thyroiditis

摘要

PurposeSelenium (Se), an essential trace element, has been implicated in pathogenesis of autoimmune thyroiditis (AIT). Most studies attributed the immune modulating effects of Se to its antioxidant properties. However, there is insufficient evidence to support the use of selenium supplementation or other antioxidants in patients with AIT. This clinical trial was designed to investigate the impact of Se and vitamin C supplementation on antithyroid peroxidase antibody (TPO-Ab) level in patients with AIT.MethodsOne hundred and two subjects aged 15-78years were randomized into three groups. Group one (GI) (n=38) was treated with 200g/day sodium selenite, group two (GII) (n=36) received 500mg vitamin C/day, and group three (GIII) (n=28) received placebo over a 3-month period. Thyroid stimulating hormone (TSH), TPO-Ab, antithyroglobulin antibody (Tg-Ab) and Se concentrations were once measured before treatment and at the end of the study.ResultsAfter 3months, TPO-Ab concentrations decreased within Se and vitamin C-treated groups, but did not change in the placebo subjects. In this regard, there was no significant difference between the groups. We also did not find any statistically significant difference in TSH and Tg-Ab levels within and between the groups. At the end of the study, Se level was significantly higher in GI compared with GII and GIII.ConclusionOur findings supported the hypothesis of antioxidant beneficial effects of Se in AIT. However, it was not superior to vitamin C, regarding its effects on thyroid-specific antibodies.