Endocrine Abstracts

Selenium (Se) is a micronutrient of vital importance to human health. It acts as an antioxidant, immunomodulator and also it is involved in the control of specific endocrine pathways. In adults, the thyroid is the organ with the highest amount of selenium per gram of tissue. The literature suggests that selenium supplementation of patients with Hashimotos thyroiditis is associated with a reduction in antithyroperoxidase antibody levels. Selenium supplementation also in mild Graves orbitopathy is associated with delayed progression of ocular disorders. The aim of this work is to evaluate the effect of selenium supplementation on progression of Graves Orbitopathy.

Design: An open-label, randomized controlled study was performed in 40 Graves-Basedows disease patients with mild form of Graves orbitopathy (GO) divided in to two groups: 1) Selenium group patients (n=18) received methimazole and selenium 200 ug for 6 months and 2) Control group patients (n=22) received methimazole alone for 6 months. Methimazole was discontinued at 24 weeks in euthyroid patients.

Results: After six months of treatment 12 of 18 (66.6%) in selenium group and 7 of 22 (31.8%) had no progression of orbitopathy (OR 1.18; P<0.05). Serum levels of free triiodothyronine/free tetraiodothyronine, thyroid-stimulating hormone receptor antibody, prevalence of moderate to severe Graves orbitopathy, thyroid volume were significantly lower in group treated with selenium than in control group after six months of treatment.

Conclusion: These results indicated that methimazole and selenium combination is more effective in reduction of Graves orbitopathy than the methimazole monotherapy.

Keywords: Graves orbitopathy, Hashimoto thyroiditis, selenium supplementation.