Clinical efficacy of selenium supplementation in patients with Hashimoto thyroiditis: A systematic review and meta-analysis

Background: To assess the clinical benefits of Selenium (Se) supplementation in patients with Hashimoto thyroiditis (HT). Methods: Eight databases were searched for randomized controlled trials. The outcomes of interest were thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), thyroid-stimulating hormone (TSH), free triiodothyronine (FT 3 ), and free thyroxine (FT 4 ). The study protocol is registered on INPLASY, DOI number is 10.37766/inplasy2022.10.0085. Results: Twenty-one studies with a total of 1610 subjects were included. Serum TPOAb was significantly reduced after Se supplementation after 3 months (standardized mean difference [SMD] = −0.46, 95% confidence interval [CI]: −0.74 to −0.18, P = .001) and 6 months (SMD = −0.80, 95%CI: −1.38 to −0.21, P = .008). The serum TgAb levels decreased at 3 months (SMD = −0.46, 95%CI: −0.79 to −0.12, P = .007) but not at 6 months. Significant effects on declining the TSH titers were found after 6 months (SMD = −0.18, 95%CI = −0.35 to −0.01; P = .03). Conclusion: Se supplementation help reduce TPOAb and TSH levels in HT patients, leading to improvements in well-being or mood. Selenomethionine is more effective than NaSe and Se-yeast in the teatment of Hashimoto thyroid.