Plasma selenium and glutathione peroxidase activity in patients with multinodular goiter

The Deiodinase and the Glutathione Peroxidase families of selenoproteins ha ve been involved in thyroid hormone economy. Whereas the consequences of Io dine deficiency on thyroid functions are well known, the effects of margina l Selenium deficiency have not been widely investigated and extended low Se lenium intakes might be also considered in the etiopathogenesis of sporadic goitre. Quantitative and functional approaches are utilized in the evaluation of bo dy Selenium status in humans since the concentration of Selenium in body fl uids and the activity of selenium dependent enzymes can give some general i nformation on either the short and long term supply of this essential trace element. With these aims, plasma Selenium was measured by PIXE and GPx activity was determined in plasma, in platelet and in erythrocyte samples of 30 patients with sporadic Multinodular Goiter (MNG) and in 14 healthy individuals for comparison. Significantly lower either Selenium levels and GPx activity wer e found in patients with respect to normal controls living in the same area . Also thyroid hormone levels were significantly reduced in patients with s poradic MNG with respect to normal controls. However, the level of thyroid hormones in patients belongs the range of normal reference interval. Our findings indicate that low Selenium status and MNG were associated in o ur patients. On the other hand, normal T-4, T-3 and TSH levels in the serum of our patients might suggest the preferential utilization of Selenium in the preservation of thyroid homeostasis during extended marginal Iodine and Selenium deficiency.