C Liu1, Y Duan, X Wu. 1. Department of Endocrinology, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China.
Abstract
OBJECTIVE: To compare the potential benefits of 36-month treatment with 6- and 18-month treatment of antithyroid drug in patients with hyperthyroidism due to Graves' disease (GD). METHODS: 183 GD patients were studied prospectively. All patients received methimazole (MMI) at decreasing doses for 6, 18 or 36 months. The relapse rates 18 months after MMI withdrawal were compared between the three therapy groups. RESULTS: The relapse rate 18 months after the discontinuation of treatment was higher in patients treated for 6 months than in those treated for 18 or 36 months. There was no significant difference between 18-month and 36-month treatment groups. At the end of therapy, serum thyroid stimulating antibody (TSAB) and TSH receptor antibody (TRAB) titers were greater in patents treated for 6 months (320 +/- 191 for TSAB and 8.72 +/- 5.23 for TRAB) and 18 months (165 +/- 87 and 4.55 +/- 4.17) than in those treated for 36 months (126 +/- 77 and 2.19 +/- 2.64), but no statistical difference was found between the three groups before MMI treatment. TSAB and TRAB titers were higher in patients who relapsed after discontinuation of MMI (287 +/- 94 and 6.14 +/- 2.37, respectively) compared with those who remained euthyroid through the 18-month follow-up period (144 +/- 61 and 1.97 +/- 1.06). CONCLUSIONS: Negative TSAB or TRAB at the end of antithyroid therapy is a good indicator for a long-term remission after treatment withdrawal. However, treatment duration greater than 18 months does not improve remission rate of GD.
OBJECTIVE: To compare the potential benefits of 36-month treatment with 6- and 18-month treatment of antithyroid drug in patients with hyperthyroidism due to Graves' disease (GD). METHODS: 183 GDpatients were studied prospectively. All patients received methimazole (MMI) at decreasing doses for 6, 18 or 36 months. The relapse rates 18 months after MMI withdrawal were compared between the three therapy groups. RESULTS: The relapse rate 18 months after the discontinuation of treatment was higher in patients treated for 6 months than in those treated for 18 or 36 months. There was no significant difference between 18-month and 36-month treatment groups. At the end of therapy, serum thyroid stimulating antibody (TSAB) and TSH receptor antibody (TRAB) titers were greater in patents treated for 6 months (320 +/- 191 for TSAB and 8.72 +/- 5.23 for TRAB) and 18 months (165 +/- 87 and 4.55 +/- 4.17) than in those treated for 36 months (126 +/- 77 and 2.19 +/- 2.64), but no statistical difference was found between the three groups before MMI treatment. TSAB and TRAB titers were higher in patients who relapsed after discontinuation of MMI (287 +/- 94 and 6.14 +/- 2.37, respectively) compared with those who remained euthyroid through the 18-month follow-up period (144 +/- 61 and 1.97 +/- 1.06). CONCLUSIONS: Negative TSAB or TRAB at the end of antithyroid therapy is a good indicator for a long-term remission after treatment withdrawal. However, treatment duration greater than 18 months does not improve remission rate of GD.