[Changes of the binding capacity of sex hormone binding globulin in patients with hyperthyroidism before and after antithyroid therapy].

We studied the change of the binding capacity of the sex hormone binding globulin (SHBG-BC) and correlated it with the serum level of thyroid hormone and sex hormone in 17 patients (10 males and 7 female) with hyperthyroidism before and during the 16 weeks of antithyroid treatment. The serum TT4, TT3, FT4I level and SHBG-BC were significantly elevated before treatment compared to normal adults. After the treatment with antithyroid drugs, serum SHBG-BC decreased significantly at 2nd weeks in female (from 312.9 +/- 39.6 to 205 +/- 18.6 nmol/L, P < 0.05) and at 8th weeks in male (from 155.7 +/- 18.6 to 109.7 +/- 7.9 nmol/L, P < 0.05). It continued to decrease to normal range (78.6 +/- 7.3 vs 65.0 +/- 24.1 nmol/L, P > 0.05) at 8th weeks in female, but was still higher than normal range (107.4 +/- 7.2 vs 41.5 +/- 10.2 nmol/L, P < 0.001) even at 16th weeks in male. The change of SHBG-BC was significantly positively correlated to the serum concentration of TT4, TT3 and FT4I(P < 0.001). In male patients the serum testosterone (T) level decreased from a high level of 41.9 +/- 6.2 nmol/L before treatment to 25.4 +/- 3.4 nmol/L at 8th weeks (P < 0.05) and to 19.8 +/- 2.8 nmol/L at 16 weeks which was in normal range. The decrease of serum T level was also positively correlated to the changes of SHBG-BC (P < 0.0001). The serum estradiol (E2) level of female patients was in the upper normal range before the antithyroid treatment.(ABSTRACT TRUNCATED AT 250 WORDS)