Efficacy of selenium supplementation for mild-to-moderate Graves ophthalmopathy in a selenium-sufficient area (SeGOSS trial): study protocol for a phase III, multicenter, open-label, randomized, controlled intervention trial

Abstract

Background The therapeutic effect of selenium has been demonstrated in mild Graves ophthalmopathy (GO) in a European region where selenium status is suboptimal. However, there is a lack of evidence to support selenium use in selenium-sufficient areas. The aim of this study is to evaluate the therapeutic effect of selenium in mild-to-moderate GO in selenium-sufficient South Korea. Methods The SeGOSS trial is a multicenter, prospective, randomized, open-label trial in South Korea. Eighty-four patients aged 19years or older with mild-to-moderate GO will be randomized to receive either vitamin B complex alone or vitamin B complex with selenium for 6months with three monthly follow-up visits. The primary outcome is comparison of the improvement in quality of life at 6months from baseline between the control and selenium groups. The secondary outcomes are intergroup differences in changes in quality of life at 3months, clinical activity of GO at 3 and 6months, thyroid autoantibody titers at 3 and 6months, and the response rate at 3 and 6months from baseline. Quality of life will be measured by questionnaire for patients with GO, and the clinical activity of GO will be evaluated by the clinical activity score (CAS). A positive response is defined as either changes in the CAS < 0 or the changes in the GO-QOL score ≥ 6. Discussion The SeGOSS study will evaluate the therapeutic potential of selenium for mild-to-moderate GO in a selenium-sufficient area and provide support in tailoring better treatment for GO.

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