Positive effects of selenium supplementation in women with newly diagnosed Hashimoto's thyroiditis in an area with low selenium status

Objective Autoimmune thyroid diseases, including Hashimoto's thyroiditis, are the most common ones among autoimmune diseases. The reported effects of selenium supplementation on the course of Hashimoto's thyroiditis are not consistent. It is therefore important to continue this line of research. Design The participants received selenium in the form of sodium selenite(IV) at a dose of 100 mu g/day for 6 months. Patients Newly diagnosed and previously untreated Hashimoto's thyroiditis with euthyroidism or subclinical hypothyroidism. A total of 36 patients (aged 20 to 52 years) qualified for this study, of whom 29 women were successfully enrolled and completed the intervention. Measurements Both before and after supplementation the following parameters in serum were tested: anti-thyroid peroxidase antibodies, thyroid function indicators, selenium as well as antioxidant status parameters and other biochemical parameters (lipid profile, glucose). Iodine supply and subjective assessment of physical and psychological health were also monitored. Results Selenium supplementation decreased significantly level of anti-thyroid peroxidase antibodies what might have had a stabilizing effect on thyroid function, as values of thyroid parameters were within normal range before and at the end of the study. Mean level of selenium among patients was not different to healthy people in Poland. Median of ioduria was within normal range. Conclusions The study shows a potential way of protective effect of selenium in limiting development of overt hypothyroidism. The increase in the concentrations of Se and SELENOP in the serum of patients verifies successful supplementation and good compliance, but did not affect the antioxidant status parameters measured.

Automated summary

Autoimmune thyroid diseases, including Hashimoto's thyroiditis, are common among autoimmune diseases. The effects of selenium supplementation on Hashimoto's thyroiditis are inconsistent. This study showed that selenium supplementation significantly decreased anti-thyroid peroxidase antibodies, potentially stabilizing thyroid function. This suggests a protective effect of selenium in limiting the development of overt hypothyroidism.