Selenium vs Control for Graves Ophthalmopathy in a Selenium-Sufficient Area: A Randomized Clinical Trial.

Importance: Graves ophthalmopathy significantly diminishes patients' quality of life due to its immune-mediated inflammatory effects on the orbital tissues. Selenium, with its antioxidative properties, has shown potential for improving Graves ophthalmopathy progression and quality of life (QOL); however, its effectiveness in selenium-sufficient regions is not well established. Objective: To determine whether selenium supplementation improves QOL in patients with mild to moderate Graves ophthalmopathy in selenium-sufficient regions. Design, Setting, and Participants: The Efficacy of Selenium Supplementation for Mild-to-Moderate Graves' Ophthalmopathy in a Selenium-Sufficient Area (SeGOSS) trial was a randomized, open-label multicenter study. Eighty-four patients with mild to moderate Graves' ophthalmopathy were enrolled; 70 completed the study. Participants were selected based on Graves ophthalmopathy diagnosis and sufficient selenium levels. Data were analyzed from October 2023 to March 2024. Interventions: Participants received selenium supplementation combined with vitamin B complex for 6 months. Main Outcomes and Measures: The primary outcome was improvements in Graves ophthalmopathy QOL (GO-QOL) scores at 6 months. Secondary outcomes included changes in GO-QOL scores at 3 months, the proportion of patients showing improvement based on GO-QOL scores, clinical activity score, and ophthalmic examinations at 3 months and 6 months, and changes in thyroid autoantibodies at 3 months and 6 months. Results: There was no improvement in changes in the total GO-QOL scores between the selenium group (31 female patients [83.8%] and 7 male patients [16.2%]; mean [SD] age, 40.8 [11.7] years) and control group (24 female patients [72.7%] and 9 male patients [27.3%]; mean [SD] age, 42.9 [14.2] years) for the primary outcome at 6 months (mean [SD], 12.2 [22.5] vs mean [SD], 11.2 [20.2]; difference, 0.9; 95% CI, -9.3 to 11.3; P = .85). However, at 3 months, a higher proportion of patients in the selenium group showed improved GO-QOL scores compared with the control group (78.4 vs 48.5%; difference, 0.30; 95% CI, 0.08-0.51; P = .01). The selenium group also had higher rates of improvement in proptosis reduction (49.5 vs 15.1%; difference, 0.31; 95% CI, 0.11-0.51; P = .01) at 3 months, though these effects were not sustained at 6 months. Conclusions and Relevance: These results suggest that selenium supplementation did not improve QOL or clinical parameters in patients with mild to moderate GO in selenium-sufficient regions at 6 months. Some potential QOL benefits noted at 3 months supports consideration of further investigation of selenium for patients seeking treatment for Graves ophthalmopathy . Trial Registration: Clinical Research Information Service Identifier KCT0004040.