Influence of physiological dietary selenium supplementation on the natural course of autoimmune thyroiditis.
OBJECTIVE
Our study aimed to investigate whether physiological doses of selenium (Se) influence the natural course of autoimmune thyroiditis (AIT).


METHODS
A total of 76 consecutive patients (65 F, 11 M, median 43, range 15-75 years) 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 μg/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 five 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.
Nacamulli
Davide
D
Endocrinology Unit, Department of Medical and Surgical Sciences, University of Padua Veneto Institute of Oncology Department of Laboratory Medicine, Padua, Italy.
Mian
Caterina
C
Petricca
Daniela
D
Lazzarotto
Francesca
F
Barollo
Susi
S
Pozza
Dina
D
Masiero
Stefano
S
Faggian
Diego
D
Plebani
Mario
M
Girelli
Maria E
ME
Mantero
Franco
F
Betterle
Corrado
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018038:Sodium Selenite / Q000008:administration & dosage*; D013954:Thyroglobulin / Q000276:immunology; D013961:Thyroid Gland / Q000473:pathology; D013967:Thyroiditis, Autoimmune / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D013972:Thyrotropin / Q000097:blood
D001323:Autoantibodies; D013972:Thyrotropin; D013954:Thyroglobulin; D007453:Iodide Peroxidase; D018038:Sodium Selenite