[The effect of statins on lipids peroxidation and activities of antioxidants enzymes in patients with dyslipidemia].

UNLABELLED: In recent studies it was observed antioxidant effects of statin independently on their hypolipemic effects. It is supposed that differences in statins pharmacological properties may cause different antioxidant actions. The aim of the study was to evaluate the effect of simvastatin, atorvastatin and pravastatin on plasma lipids, thio-barbituric acid reactive substances (TBARS) concentrations in the isolated erythrocytes membranes, activities of antioxidants enzymes in erythrocytes: catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) in patients (pts) with dyslipidemia.

MATERIAL: The study comprised 114 pts, including 94 pts with dyslipidemia without concomitant chronic diseases and 20 healthy volunteers. Pts were qualified to treatment with statins if their LDL-cholesterol concentration (LDL-C) was above 160 mg/dL (4.1 mmol/l), total cholesterol (TC) > 250 mg/dl (6.5 mmol/l) and triglicerydes (TG) < 400 mg/dl (4.5 mmol/L). Pts were randomized to three groups: group I-n = 31 pts treated with atorvastatin (10 mg/d); group II-n = 31-simvastatin (20 mg/d), group III-n = 32 pravastatin (20 mg/d).

METHODS: After 4 and 12 weeks of active treatment the following parameters were determined: TC, HDL-C, TG (by enzymatic method using bioMerieux tests); LDL-C was calculated from the Friedewald formula, TBARS concentrations (by method of Stock and Dormandy), CAT (method of Bartosz et al.), GSH-Px (method of Rice-Evansa et al.), SOD (method of Misra) activities.

RESULTS: During statin therapy significant decrease of TC, LDL-C, TG was observed, both after 4 and 12 weeks, as compared with the initial values. All statins significantly decreased TBARS concentrations either 4 or 12 week therapy at all. The activities of antioxidants enzymes (CAT, GSH-Px, SOD) significantly increased after 4 weeks therapy in patients treated with atorvastatin and simvastatin. During pravastatin therapy it was noticed only increase of CAT activity after 12 weeks.

CONCLUSION: In patients with dyslipidemia without clinical symptoms of atherosclerosis atorvastatin, simvastatin and pravastatin decreased similar TBARS concentrations in membrane in the isolated erythrocyte membranes. It was observed a significant increase of the antioxidant enzyme activities during atorvastatin and simvastatin treatment. Pravastatin therapy caused increase the CAT activity without any effect on the activities of GSH-Px and SOD.