Endocrine Abstracts

In the last 20 years an increasing number of European patients with autoimmune thyroiditis are supplemented with selenium in case of elevated thyroid autoantibody levels. However, a multicenter research trial in the United States suggested that selenium supplementation might increase the incidence of type 2 diabetes. The aim of this small study was to assess whether selenium supplementation in patients with autoimmune thyroiditis has any effect on carbohydrate metabolism without and during pregnancy. Thirty patients with autoimmune thyroiditis and twenty pregnant women were treated with 2x100 µg selenium. Twenty control patients with autoimmune thyroiditis and 10 control pregnant women did not receive selenium. The following parameters were determined in all patients: fasting glucose and insulin concentration, TSH, fT4, thyroid autoantibody levels. After six months, the following parameters were determined: TSH, fT4, thyroid autoantibodies, fasting glucose, insulin, and an oral glucose tolerance test was performed. Serum selenium concentration was measured in order to confirm adherence to treatment. Statistical analysis was performed using the Microsoft Excel program. The thyroid autoantibody concentrations decreased varyingly. Insulin resistance measured as HOMA-index increased in patients whose serum selenium concentration exceeded the physiological range after six months of treatment with selenium. The oral glucose tolerance test, however, did not indicate type 2 diabetes in these patients. There was no difference regarding the frequency of gestational diabetes between the two groups of pregnant women (both 10%). Selenium supplementation with 200 µg has minimal effects on carbohydrate metabolism in this cohort of Hungarian patients with autoimmune thyroiditis.