Effect of additional selenium on the levels of serum thyroid peroxidase antibody in patients with Graves disease treated with 131I

Abstract

Objective To explore the effect of additional selenium on the serum levels of thyroid peroxidase antibody (TPOAb) after treatment of Graves disease with 131I. Methods A total of 266 patients with TPOAb levels between 10 and 1300 IU/ml participated in this study. TPOAb levels within 10 IU/ml to 60 IU/ml were considered negative, and levels greater than 60 IU/ml were considered positive. All patients were randomly divided into control (n=112) and selenium treatment group (n=154) . After treatment with 131I, the control group received conventional therapy, whereas the selenium treatment group received additional selenium (100 μg twice a day) . The TPOAb levels and positive ratios of the two groups were compared with pre-therapy levels after treatment for 6 and 12 months. Results After 6 months, the TPOAb levels in both groups significantly increased compared with the pre-therapy levels (control group: Z=-2.084, P 0.05) . After 12 months, the TPOAb levels in the control group did not change significantly compared with the pre-therapy levels (Z=-1.538, P>0.05) , whereas the TPOAb levels in the selenium treatment group significantly decreased compared with the pre-therapy levels (Z=-5.465, P 0.05; selenium treatment group: χ12=0.023,χ22=0.340, both P>0.05) . Overall, the positive ratios were not statistically significant between the two groups (χ12=0.001,χ22=0.366, both P>0.05) . Conclusion Additional treatment with selenium after 131I therapy for Graves disease can effectively decrease the TPOAb levels, especially for patients with high initial TPOAb levels. Key words: Selenium; Iodine radioisotopes; Graves disease; Thyroid peroxidase antibody