Activity of antioxidative enzymes and concentration of malondialdehyde as oxidative status markers in women with non-autoimmunological subclinical hyperthyroidism

Abstract

Introduction: The recent investigations point out the significant role of oxidative stress in the development of thyroid gland disease. The present study was designed to investigate the variation of oxidative stae in women with non-autoimmunological subclinical hyperthyroidism.
Material and methods: The study was conducted on 20 females with non-autoimmunological subclinical hyperthyroidism and 15 healthy women. Manganase-containing superoxide dismutase (Mn-SOD) and extracellular superoxide dismutase (EC-SOD) plasma activity, and malondialdehyde (MDA) plasma concentration were measured.
Results: EC-SOD plasma activity was significantly higher in women with subclinical hyperthyroidism when compared with the control group (13.3 ± 2.1 vs. 10.9 ± 1.4 NU/ml; p < 0.05), unlike Mn-SOD (4.2 ± 0.5 vs. 4.0 ± 1.0 NU/ml). MDA plasma concentration increased significantly in women with subclinical hyperthyroidism (3.5 ± 1.2 vs. 2.0 ± 0.6 μmol/l; p < 0.05).
Conclusions: The increased EC-SOD plasma activity may reflect disturbances of oxidative state in subclinical hyperthyroidism. Parallel increase of MDA plasma concentration may indicate enhancement of lipid peroxidationin in patients with subclinical hyperthyroidism.