Selenium supplementation could restore euthyroidism in subclinical hypothyroid patients with autoimmune thyroiditis

Intriduction: The thyroid is an organ with one of the highest selenium concentrations, containing many selenoproteins implicated in thyroid hormone metabolism. Treatment with levothyroxine has been recommended for all subclinical hypothyroid patients with TSH levels > 10 mU/L, whereas for those with TSH < 10 mU/L treatment remains controversial. Aim: A randomised controlled prospective study was performed to investigate the effects of Se treatment on patients with autoimmune thyroiditis and mild sub-clinical hypothyroidism (TSH < 10 mU/L). Material and methods: A total of 196 patients with autoimmune thyroiditis were recruited in the study. Patients were assigned to receive (case) or not receive (control) an oral selenomethionine treatment. Cases received 83 mcg selenomethionine/day orally for four months. All the patient's charts were submitted to thyroid hormonal profile (TSH, fT4) and TPOAb evaluation upon enrolment and at the end of the study. Results: In total 192 patients completed the study. Cases and controls were superimposable for age, gender, thyroid hormonal profile, and TPOAb levels. At the end of the study, 33/192 (17.2%) participants restored euthyroidism (Responders). Responders were significantly more frequent among Cases than Controls (30/96 [31.3%] vs. 3/96 [3.1%], p < 0.0001). Conclusion: Selenium supplementation could restore euthyroidism in one third of subclinical hypothyroidism patients with autoimmune thyroiditis.