Predictors of relapse in graves' hyperthyroidism after treatment with antithyroid drugs

Abstract

Background: Choice of the treatment for patients with Graves' hyperthyroidism depends on local preference, the higher recurrence risk, comorbidities, and the patient's preferences. About half of the patients relapse after a course of a standard antithyroid drug (ATD) therapy for Graves' disease. Objectives: The objective of this study was to determine the clinical and biochemical features of Graves' hyperthyroidism that can predict the relapse of the disease after a standard course of ATD therapy. Patients and Methods: We conducted a retrospective 6-month study of 79 patients with Graves' hyperthyroidism who were treated with ATD (carbimazole) therapy for 12–18 months and went into remission for at least 1 year after ATD withdrawal. Results: The relapse rate in Graves' hyperthyroidism after 1 year in remission was 40.5%; patients with younger age (<40 years) and with severe biochemical disease correlated significantly with relapse. Gender, presence of a palpable goiter, orbitopathy, and smoking habits were not significant predictors of relapse, perhaps because of the small sample size. Conclusions: Forty percent of Graves' hyperthyroidism relapsed after 1 year of remission. Younger age and severe biochemical disease at diagnosis predicted relapse.