No abstract

The outcome of 131I therapy for 109 patients with Graves' disease was analysed according to pretreatment laboratory data including thyrotropin receptor antibody (TRAb) activities. Forty-five percent of patients became euthyroid, and 13% of patients became hypothyroid within one year after 131I therapy. Forty-two percent of patients remained hyperthyroid one year after 131I therapy. Pretreatment values for serum T4, T3, and the estimated weight of the thyroid were significantly higher in the hyperthyroid group. The mean for the TRAb index of the hyperthyroid group was significantly higher than that of the euthyroid group. Life table analysis revealed a significant effect of the TRAb index on the rate of hyperthyroidism after 3 months or later. These results appear to suggest that the TRAb index is one of the factors which influence the outcome of 131I therapy for Graves' disease.

Objective β-adrenergic antagonists (β-blockers) are often used to attenuate the hyperadrenergic symptoms of Graves' disease (GD), including palpitation. Although β-blockers reduce the heart rate, cardiac output and oxygen consumption, no firm evidence exists regarding the effects of combined therapy with β-blockers and anti-thyroid drugs. The objective is to elucidate the effects of β-blockers on anti-thyroid drug therapy in GD. Methods Patients newly diagnosed with mild GD were randomly assigned to receive methimazole with or without β-blockers in a prospective multi-center survey. The heart rate and thyroid function were measured and the quality of life was assessed using original and SF-36 questionnaires at 0 and 4 weeks. Results A total of 28 patients were enrolled in the study. Fourteen patients (one man, 13 women) were randomly assigned to the group treated with β-blockers and 14 patients (one man, 13 women) were randomly assigned to the group not treated with β-blockers. Although no significant differences in the improvement of thyroid function were observed between the two groups, the heart rates improved more significantly in the group treated with β-blockers. Specific symptoms, such as easy fatigability and shortness of breath, also improved more significantly with the β-blocker treatment. In addition, 'physical functioning' assessed with the SF-36 questionnaires significantly improved only in the group treated with β-blockers. Conclusion Although β-blockers may not reinforce the effects of anti-thyroid drugs on thyroid function, at least during the course of one month, they are effective in reducing heart rates and ameliorating specific symptoms in patients with mild GD.

These results indicate that (1) the TBII index and TSAb activity decreased over a period of more than 2 years after 131I therapy for Graves' disease, and (2) the TBII index before treatment may influence the long-term outcome of 131I therapy.