Predictors of Biochemical Response to Antithyroid Drugs in Graves Disease

After careful consideration, the Endocrine Society canceled its annual meeting (ENDO 2020), which was set to take place in San Francisco, California, from March 28 to 31, 2020, because of concerns regarding coronavirus disease 2019 (COVID-19). Research findings that were scheduled to be presented at the meeting have been published in a supplemental issue of the Journal of the Endocrine Society. The society is hosting ENDO Online, a complimentary virtual event featuring on-demand and live programming, from June 8 to 22, 2020, to provide a platform for continued learning and research exhibition. For more information, visit the Endocrine Society’s website.

The presence of Graves orbitopathy, thyroid antibody levels, goiter size, and occurrence of hypothyroidism may predict treatment response to antithyroid drugs in Graves disease, according to research results intended to be presented at the annual meeting of the Endocrine Society (ENDO 2020).

Antithyroid drugs are known to produce variable responses and factors that predict treatment response remain unknown. The objective of this study was to identify predictors of poor treatment response to antithyroid drugs in Graves disease.

Researchers evaluated 97 patients with incident Graves disease who were treated with antithyroid drugs for 14 days or longer between 2009 and 2019. Most patients were women (70.1%) and most had never smoked (64.9%). The study population had a median goiter size of 40 g, a median thyrotropin receptor antibody (TRAb) concentration of 8.1 mU/L at presentation, and a median age of 50 years. All 97 patients were started on methimazole at a median dose of 20 mg and 13.4% of patients had Graves orbitopathy at baseline.

The median times from presentation until biochemical improvement and euthyroidism were 120.9 days and 251 days, respectively. Patients with Graves orbitopathy at presentation were more likely to have biochemically persistent disease (biochemical improvement after >6 months) compared with patients who did not have Graves orbitopathy (38.5% vs 11.1%; P =.024). In addition, patients with TRAb concentrations of ≥8.0 mU/L or a goiter size of ≥30 g had a greater prevalence of biochemically persistent disease, but these trends were not statistically significant.

Conversely, biochemically responsive Graves disease (biochemical improvement at ≤6 months) was associated with a higher frequency of hypothyroidism during treatment with antithyroid drugs (P =.047).

The researchers suggested that their findings may help clinicians estimate treatment response to antithyroid drugs.

Reference

El Kawkgi OM, Li D, Vallejo S, et al. Anti-thyroid drug response in Graves’ disease: predictors of biochemically persistent disease. J Endocr Soc. 2020;4(suppl 1):SAT-423.

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