The evaluation of selected oxidative stress parameters in patients with hyperthyroidism

Introduction. Hyperthyroidism induces the acceleration of the basic metabolism and increases cellular oxygen utilization, consequently intensifies reactive oxygen species production and disturbs the oxidantantioxidant balance. Objectives. The objective of this study was to evaluate the selected oxidative stress parameters in patients with hyperthyroidism by analysis of the reactive oxygen species neutralizing enzymes activity – superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and catalase (CAT), the estimation of free radical processes intensity – concentration of malondialdehyde (MDA), sulfhydryl groups (SH) in proteins and by quantification of the serum total antioxidant status (TAS). Patients and methods. Twenty-seven patients treated for hyperthyroidism and 12 healthy individuals were enrolled in the study. Enzyme activity (SOD, GSHPx, CAT), MDA and concentration of SH groups were analysed in erythrocytes, while TAS was measured in serum. Results. Patients with hyperthyroidism compared with healthy subjects were characterized by a higher GSHPx activity in erythrocytes, lower serum TAS, the lower content of SH groups in proteins and the lower MDA concentration in erythrocytes. Conclusions. Our results suggest that hyperthyroidism increases oxidative stress and disturbs oxidant-antioxidant balance in the body. Thyreostatic treatment, if it does not lead total metabolic correction, can only reduce oxidant-antioxidant disorder, but it does not eliminate it entirely.