Long-term follow-up result of antithyroid drug treatment of Graves’ hyperthyroidism in a large cohort

OBJECTIVE: This study evaluated the efficacy of antithyroid drugs (ATDs) and risk factors associated with the recurrence of Graves’ hyperthyroidism using a comprehensive retrospective cohort. METHODS: We included 1829 patients newly diagnosed with Graves’ hyperthyroidism, with sufficient follow-up data. Clinical outcomes of the patients and risk factors associated with recurrence-free survival, including the changes in thyrotropin receptor antibody, were evaluated. RESULTS: The median age of the patients was 44.5 years, and 69% were female. Among the patients, 1235 had a chance to withdraw ATD after a median of 23 (interquartile range (IQR) 17.0–35.5) months of treatment. The first remission rate was 55.6% during a median of 72.7 months of follow-up. After the first recurrence, 95% of patients underwent the second course of ATD treatment for a median of 21.1 (IQR 14.8–31.7) months, and the remission rate was 54.1%. During a median of 67 months of follow-up, 7.7% of patients underwent surgery, and 10.5% underwent radioactive iodine therapy. Approximately 30% were still on ATD therapy for recurrent disease or prolonged low-dose maintenance. Younger age (<45 years), male sex, and fluctuating or smoldering of TRAb levels were independent risk factors of the first recurrence after ATD treatment. CONCLUSIONS: ATD treatment is an acceptable option for the initial treatment of Graves’ hyperthyroidism as well as for recurrent disease. The optimal treatment period for ATD treatment needs to be determined using the individual risk factors of recurrence.