The impact of propylthiouracil therapy on lipid peroxidation and antioxidant status parameters in hyperthyroid patients

This study was performed on 17 hyperthyroid patients and 15 healthy controls. The patients were under propylthiouracil (PTU) therapy at a dosage of 3 x 100 mg/day for one month. Blood samples, taken at the beginning and on the 30th day of therapy, were analyzed for hormonal parameters (T3, T4, TSH), lipid peroxidation endproduct [thiobarbituric acid reactive substances (TBARS)] and antioxidant status parameters: glutathione (GSH), glutathione peroxidase (GSH-Px) and CuZn superoxide dismutase (CuZn SOD). Hyperthyroid patients were observed to have significantly higher TBARS, GSH and CuZn SOD levels than controls (P < 0.05, P < 0.001, P < 0.001, respectively). PTU therapy caused a relief in oxidative stress as reflected by significantly decreased TBARS levels (P < 0.001) and a selective modification in the antioxidant status parameters: significant decreases in GSH and CuZn SOD levels (P < 0.001) and a significant increase in GSH Px (P < 0.01) activity. Our findings suggest a selective modification of the antioxidative profile in hyperthyroidism. PTU should also be considered as an in vivo antioxidant, in addition to its antithyroid action.