The Management of Hyperthyroidism Due to Graves' Disease in Japan in 1988

Abstract

The management of hyperthyroidism due to Graves' disease in Japan was the subject of a survey of the members of the Japan Thyroid Association (JTA), and the results were compared to those of the European Thyroid Association (ETA). In the questionnaire, in vivo and in vitro diagnostic procedures, the choice ot treatment and the details of the treatment for a patient with typical, moderate and uncomplicated hyperthyroidism due to Graves' disease was at first asked, and eight variations with a single alternative were proposed to evaluate how each alternative would affect the choice of treatment. For the diagnostic procedures, thyroid uptake/scintigraphy was carried out by approximately 60% of the respondents and the isotope mainly used was ¹²³I. The number of in vitro tests used for diagnosis averaged 8.1±1.8 tests. Measurements of basal TSH and free T₄ were the most frequent tests performed to confirm the diagnosis of hyperthyroidism (94 and 80%, respectively). Determinations of microsomal, thyroglobulin and TSH-receptor autoantibodies were also employed by many respondents (96, 96 and 77%, respectively). On the other hand, the free T₄ index and TRH test were less frequently employed. In the teatment of these patients, antithyroid drug treatment was the first choice, and surgery was not, in general, regarded as a primary therapy except in a patient with a large goiter. The frequency of the respondents who advocated radioiodine therapy was considerably higher for patients with recurrences and old age. No respondents proposed radioiodine therapy for young patients. Specialists tended to favor their own specialist treatment regimens. The initial dose of antithyroid drugs was reduced according to thyroid function, and withdrawal of antithyroid drug treatment was determined by some specific criteria (basal TSH in supersensitive assays, TSH-receptor autoantibodies, T₃ suppression test, etc.). The aim of radioiodine therapy and surgery was to restore euthyroidism. The significant differences between the results from the JTA and those from the ETA were as follows radionuclide used for thyroid uptake/scintigraphy was mainly ¹²³I in Japan, but ¹³¹I in Europe, the number of diagnostic studies in Japan was more than that in Europe, and the dosage of antithyroid drugs was reduced according to thyroid function and discontinued based on certain specific criteria in Japan, but after fixed periods in Europe. These results may represent actual trends in how hyperthyrodism due to Graves' disease is managed in specialist clinics in Japan today and the differences between the JTA and the ETA.