Spontaneous normalisation of thyroid hormones in Graves

Sophie Langdon; May Loo; Tee Su Ann; Kathryn Stewart; Vasileios Tsatlidis; Kilimangalam Narayanan; Salman Razvi

doi:10.1530/endoabs.117.P225

P225

Prev Next

Section Contents Cite

Endocrine Abstracts (2026) 117 P225 | DOI: 10.1530/endoabs.117.P225

SFEBES2026 Poster Presentations Thyroid (34 abstracts)

Spontaneous normalisation of thyroid hormones in Graves’ hyperthyroidism

Sophie Langdon ¹ , May Loo ¹ , Su Ann Tee ¹ , Kathryn Stewart ¹ , Vasileios Tsatlidis ¹ , Kilimangalam Narayanan ¹ & Salman Razvi ^1,2

Author affiliations

¹Department of Endocrinology, Gateshead Health NHS Foundation Trust, Gateshead, United Kingdom; ²Translational and Clinical Research Institute, Newcastle University Centre for Life, Newcastle upon Tyne, United Kingdom

Background: Monitoring thyroid hormones is essential in the management of Graves’ hyperthyroidism, but the magnitude of meaningful change of thyroid hormones over a few weeks without treatment remains uncertain. Furthermore, the proportion of patients with hyperthyroidism who normalise thyroid hormones spontaneously without treatment is unknown, potentially leading to unnecessary therapy in some individuals.

Methods: We reviewed FT4 measurements in patients with Graves’ hyperthyroidism who had two blood tests performed weeks apart, prior to antithyroid drug therapy. Analytical and biological variation of FT4 was considered to estimate the reference change value (RCV). Changes were classified as significant if FT4 normalised or if the percentage change exceeded the combined expected variability (>20%). Long-term clinical data was analysed to evaluate the significance of these short-term changes. Regression analyses were performed to assess the magnitude of change and its predictors.

Results: Among 233 patients with high baseline FT4 tests, 32 (13.7%) showed spontaneous normalisation of FT4 levels on repeat testing after a median (IQR) of 33 (54-21) days. During longer term follow-up, 18 (56%) of these 32 patients remained euthyroid without treatment, whereas 14 (44%) ultimately required therapy. Baseline FT4 concentration was the only independent predictor of spontaneous normalisation, with lower initial levels associated with a higher likelihood of normalisation (odds ratio 0.86; 95% CI 0.78 – 0.93).

Conclusion: Spontaneous normalisation of FT4 occurs in approximately 1 in 7 patients with Graves’ hyperthyroidism, particularly among those with mildly elevated baseline levels. These findings support a cautious approach to immediate initiation of antithyroid therapy in selected patients, emphasising the importance of close biochemical monitoring to identify those who may deteriorate over time. Recognising the potential for spontaneous resolution can help avoid unnecessary treatment and optimise patient management.