Selenium Supplementation May Decrease Thyroid Peroxidase Antibody Titer via Reducing Oxidative Stress in Euthyroid Patients with Autoimmune Thyroiditis

Abstract

Objective. Selenium, as an antioxidant, has been implicated in the development of autoimmune thyroiditis (AIT). Many studies showed selenium supplementation could decrease thyroid autoantibodies in patients with AIT. However, the underlying mechanisms have not been well determined. Therefore, we performed a clinical study to investigate the possible mechanism of beneficial effects of selenium treatment on AIT patients. Methods. Forty euthyroid patients with AIT were randomized into two groups. Group I was treated with 200 μg/day selenium supplementation, and group II received a placebo over a 3-month period. Thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), antithyroglobulin antibody (TgAb), malondialdehyde (MDA), total antioxidant capacity (TAC), and superoxide dismutase (SOD) were measured before and 3 months after treatments. Additionally, twenty healthy volunteers also served as a control group for the evaluation of such parameters in basic condition. Results. Totally, 32 patients (group I, n = 18; group II, n = 14) completed the clinical study and were incorporated into the statistics. MDA level was higher and SOD activity and TAC were lower in patients compared to healthy individuals. After 3 months, TPOAb titer significantly decreased within group I (P<0.001) but did not change within group II (P=0.001). There were also no statistically significant changes in TSH and TgAb titers within the two groups (all P>0.05). Additionally, decreased MDA level (from 6.8 ± 1.3 nmol/ml to 4.9 ± 0.7 nmol/ml; P<0.001) and increased TAC (from 10.0 ± 1.9 mmol/l to 12.9 ± 3.1 mmol/l; P=0.003) and SOD activity (from 72.3 ± 10.3 U/ml to 84.3 ± 13.2 U/ml; P=0.007) were simultaneously observed after 3 months’ selenium treatment. Moreover, there was a negative correlation between TAC and TgAb/TPOAb and a positive correlation between MDA and TgAb/TPOAb in AIT patients. Conclusions. Our findings support the hypothesis that selenium treatment could decrease TPOAb titer via enforcing the defense against oxidative stress in euthyroid patients with AIT, which may be a potential underlying mechanism.

The rationale for selenium supplementation in patients with autoimmune thyroiditis, according to the current state of knowledge

“…intervention in the first group. The authors concluded that Se alleviates the thyroid autoimmune process by improving body antioxidative status [31]. Se supplementation (60 and 180 μg/day) significantly reduced proinflammatory cytokine release mediated by INF-g (CXCL-9 and 10) in AIT euthyroid females who were not treated with LT4 in comparison to the placebo group.…”

Metabolic Characteristics of Hashimoto’s Thyroiditis Patients and the Role of Microelements and Diet in the Disease Management—An Overview

“…Moreover, TPOAb and TgAb decreased after six months of Se supplementation compared with baseline [ 87 ]. Tian et al confirmed that Se supplementation decreased TPOAb titer by enhancing defense against oxidative stress in euthyroid patients with AIT [ 30 ]…”

“…In addition to the use of LT4, an appropriate diet and supplementation may be an important aspect of the treatment process. Se supplementation is associated with a significant decrease in TPOAb [ 30 , 31 ]. On the other hand, inadequate dietary Se intake may exacerbate HT [ 2 , 4 , 7 ].…”

The Cross-Talk between Polyphenols and the Target Enzymes Related to Oxidative Stress-Induced Thyroid Cancer

“…Numerous studies have demonstrated that selenium administration can help individuals with autoimmune thyroiditis reduce thyroid autoantibodies. Selenium therapy has been shown to lower TPO antibody titers in euthyroid individuals with autoimmune thyroiditis by strengthening the defense against oxidative stress and scavenging free radicals [ 86 ].…”