Endocrine Abstracts

The standard first-line therapy for uncomplicated Graves’ hyperthyroidism is 12-18 months of anti-thyroid drugs (ATD) in most centres, with about 50% chance of long-term remission. However, as sensitive FT3 assays were introduced since this became established practice in the 1980s, there are no good data that inform the outcome or natural history of mild Graves’ disease, which is now routinely detected and treated. The outcome of 87 patients with mild Graves’ disease, defined as TSH ≤0.05 mU/l, FT4 <30 pmol/l, FT3 <9.0 pmol/l, and TRAb 1.8-5.0 IU/l was followed in the 2 largest centres in Tyne & Wear. Patients with eye disease and those who did not tolerate ATD were excluded. Fifteen patients (17%) had spontaneous remission of hyperthyroidism that was sustained for 12 months without treatment. Thyroid status at one year after stopping treatment was available for 52 patients who completed at least 12 months of ATD (median treatment length was 18 months). Forty five patients (87%) remained in euthyroid (in remission) and 7 (13% relapsed). Outcome of ATD was not available for 20 patients for several reasons (9 patients who did not complete 12 month’s ATD, 6 patients did not stop ATD, 4 patients stopped the ATDs but have not completed the 12 months follow up yet and 1 patient made a personal choice for RAI). Treatment of mild Graves’ hyperthyroidism is not always necessary, as spontaneous remission is not infrequent (17%). In addition, 12 months or more of ATD treatment gives an excellent outcome (87% remission). Shorter treatment courses would have fewer side-effect and use less NHS resource, so should be considered.