A recent randomized clinical trial investigated the efficacy of selenium supplementation in patients with mild-to-moderate Graves ophthalmopathy in selenium-sufficient regions. In research conducted across multiple centers, the investigators found no significant benefit of selenium in improving quality of life or clinical outcomes at 6 months. However, secondary analyses suggested potential short-term improvements at 3 months.

The Efficacy of Selenium Supplementation for Mild-to-Moderate Graves’ Ophthalmopathy in a Selenium-Sufficient Area trial was a prospective, randomized, open-label study conducted at four tertiary medical centers in South Korea. The study, recently published in JAMA Ophthalmology, enrolled 84 participants diagnosed with mild to moderate Graves ophthalmopathy (GO), as defined by the 2021 European Group on Graves’ Orbitopathy guidelines. Patients were required to have stable thyroid function and no history of prior orbital radiation, biologic treatments, or recent corticosteroid use.

Participants were randomly assigned in a 1:1 ratio to receive either selenium supplementation (200 µg/day) combined with vitamin B complex or vitamin B complex alone for 6 months. The primary outcome was the change in GO quality of life (QOL) scores at 6 months; specifically assessments of visual function and appearance-related QOL measures. Secondary outcomes included GO-QOL improvement at 3 months, change in clinical activity score (CAS), changes in proptosis and lid retraction, and thyroid autoantibody levels.

At 6 months, there was no statistically significant difference in GO-QOL scores between the selenium and control groups (mean difference = 0.9; 95% confidence interval = −9.3 to 11.3; P = .85). However, at 3 months, a greater proportion of selenium-treated patients experienced a GO-QOL improvement (78.4% vs. 48.5%; P = .01). Reduction in proptosis was significantly greater in the selenium group at 3 months as well (49.5% vs. 15.1%; P = .01), but this benefit was not maintained at 6 months. CAS scores decreased in both groups, but the difference was not statistically significant at any time point. No significant changes were observed in thyroid-stimulating immunoglobulin levels or other thyroid autoantibody markers.

“Selenium supplementation…[may have] potential as an adjunct therapy for GO management,” the researchers, led by Hwa Young Ahn, MD, PhD, of the Department of Internal Medicine at the Chung-Ang University College of Medicine in Seoul, wrote.

These results contrast with prior studies that were conducted in selenium-deficient populations, where selenium supplementation was associated with significant improvements in GO severity and QOL scores. In addition to the regional difference, the researchers also noted that their study targeted more patients with inactive and stable GO. The vitamin B complex given in conjunction with selenium may have reduced differences in GO symptom improvement because of selenium. More severe fibrosis, which is associated with longer disease duration, may have also reduced the response to selenium treatment. “It seems possible that the effects of selenium supplementation may vary depending on the severity of ophthalmopathy and selenium status,” the researchers wrote.

They concluded, “These findings support consideration of further investigations of selenium for GO patients before establishing guidelines for its use in clinical practice.”

No conflicts of interest were reported.