Biochemical evaluation of some indices of oxidative stress in patients with hyperthyrodism before and after treatment

ABSTRACT

This study aimed to evaluate changes in plasma malondialdehyde, total thiol concentration and total antioxidant activity in newly diagnosed Graves' disease and toxic multinodular goiter patients prior to antithyroid treatment and after restoration of stable euthyroid state. Forty subjects were included in this study. Thirty patients with hyperthyroidism, which were classified into two groups, the first [group I] Comprised 15 patients with hyperthyroidism due to untreated Graves' disease, and the second [group II] Comprised 15 patients with hyperthyroidism due to untreated toxic multinodular goiter. Ten patients of each group were treated pharmacologically with antithyroid drug carbimazol [30 mg/day for 8 weeks]. Total thyroxin [T4], total triiodothyronine [T3], TSH, malondialdehyde, total thiol concentration and total antioxidant activity were estimated before initiation of treatment. After apparent attainment of euthyroid state, all tests were repeated for ten of the patients with Graves' disease and ten of the patients with toxic multinodular goiter. The results of this study revealed that there were a statistically highly significant increase in plasma malandialdehyde [MDA], a significant decrease in plasma thiol and very highly significant decrease in total antioxidant activity in both patient groups when compared to healthy controls. After treatment, plasma MDA levels were highly significantly decreased and total antioxidant activity was very highly significantly increased in both patient groups when compared to control one. As regard thiol, it was significantly increased in group I only. From this study it could be conclude that, intensification of lipid and protein peroxidation process and the impairment of plasma antioxidant activity in patients with hyperthyroidism due to Graves' disease or toxic multinodular goiter confirm the presence of oxidative stress and the disturbances in the antioxidant systems might be an indicator of patients' susceptibility to free radical damage. So, supplementation of antioxidants as an adjuvant to medical antithyroid treatment could help to prevent oxidative damage in hyperthyroid patients. Also, we suggest that measuring oxidative stress parameters could be a better way of follow up of thyroid state improvement both from the chemical and economic point of view