Influence of physiological dietary selenium supplementation on the natural course of autoimmune thyroiditis.
Clin Endocrinol (Oxf). 2009 Dec 18. PMID: 20039895
Abstract Objective: Our study aimed to investigate whether physiological doses of selenium (Se) influence the natural course of autoimmune thyroiditis (AIT). Design and Patients: 76 consecutive patients (65F, 11M, median 43, range 15-75 yrs) with AIT, normal or slightly elevated TSH, and fT4 within the normal range were divided into two groups: Group 0 (30 cases) was given no treatment while Group 1 (46 cases) was treated with sodium selenite 80 mug/day as a single oral dose for 12 months. Thyroperoxidase and thyroglobulin autoantibodies (TPO-Ab; Tg-Ab), TSH, fT4 and urine iodine concentrations (UIC) were measured at baseline and after 6 and 12 months of follow-up. Thyroid ultrasonography (US) was performed at each follow-up point. Echogenicity was measured by histographic analysis of gray-scale pixels (gsp) ranging from 0=black to 255=white. Results: Thyroid echogenicity decreased significantly in both groups after 6 months, but after 12 months, it had changed no more in Group 1, whereas it had dropped further in Group 0. No significant variation in TPO-Ab or Tg-Ab levels was observed between the two groups after 6 months, but both values decreased significantly after 12 months in Group 1, and 5 patients in this group became negative for TPO-Ab. TSH and FT4 showed no significant variations in either group. Conclusions: Dietary supplementation with physiological doses of Se seems to be effective in preventing a reduction in thyroid echogenicity after 6 months of treatment, and in reducing TPO-Ab and Tg-Ab after 12 months, but does not modify TSH or FT4.