Abstract:

Objective   To observe the change of serum selenium level in different stages of Graves′ disease and to investigate its role in the recurrence of the disease. Methods   90 cases of Graves′ disease were divided into 3 groups: the newly diagnosed group(n=30), the remission group(n=30) and the recurrence group(n=30). 30 normal persons were served as the control group. The serum selenium level was determined by atomic fluorescence spectrometry, the serum TRAb level was determined by ELISA, the serum GSH-Px level was determined by colorimetric method, the serum MDA level was determined by thiobarbituric acid method, and the levels of serum thyroid hormones including FT3 and FT4, TPOAb and TGAb, were determined by electrochemiluminescence. Results   The levels of selenium in the new diagnosed group and the recurrence group were (78.26±19.31)μg/L and (78.86±15.44)μg/L respectively, which were significantly lower than that of the control group(103.01±17.63)μg/L(P<0.01). There was no significant difference between the remission group and the control group(P>0.05). The selenium level of the recurrence group had no significant difference compared with that of the new diagnosed group(P>0.05), but was significantly lower than that of the remission group(P<0.01). The correlation analysis showed that the serum selenium level was in positive correlation with the GSH-PX level(P<0.05), but was in no correlation with the levels of FT3、FT4、TGAb、TPOAb and MDA(P>0.05). The level of serum selenium was in negative correlation with the TRAb level in all of the three groups(P<0.05). Conclusion   Serum selenium may be involved in the occurrence and recurrence of Graves′ disease by affecting the levels of GSH-PX and TRAb.

Key words: Graves′ disease; Selenium; Thyroid autoantibody; Antioxidation