The most important risk factors contributing to the development of atherosclerosis include lipid disorders and the predisposition to early ischaemic heart disease in the family. Atherosclerotic process proceeds with age and it develops as a result of oxide LDL modification at the level of vascular wall. Oxygen-free radicals take part in this process, which may probably be opposed by the antioxidant system of the body. The aim of this study was to compare the intensity of lipid peroxidation and the activity of antioxidant enzymes in children from the families with the risk of early atherosclerosis and in children without such predisposition. The activity of katalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined and the concentration of malonic dialdehyde - a lipid peroxidation marker was established. The study was conducted on 76 children aged 4-17 years, mean age 12&plusm;0.6 years. The risk group consisted of 56 patients with the history of hypercholesterolaemia and early atherosclerosis in the members of their families up to 45 years of age. Control group was formed of 20 subjects without such history. MDA concentration as well as the activity of antioxidant enzymes were determined with the use of adequate methods of spectrophotometry. The results obtained were subject to statistical analysis. The activity of antioxidant enzymes displayed considerable fluctuations in both groups of children, but these differences remained statistically insignificant in all the cases. Higher MDA concentrations in serum and in erythrocytes were observed in the risk group. These differences proved statistically significant (α 0.05). On the basis of the present study and the analysis performed, it was found that the activity of antioxidant enzymes (CAT, SOD, GSH-Px) cannot serve as a parameter differentiating between children from the families with the risk of early atherosclerosis and children without such predisposition. Children with positive family history of hypercholesterolaemia and early atherosclerosis may demonstrate intensive lipid peroxidation, but this hypothesis requires further investigations.

Keywords: antioxidant enzymes, Lipid Peroxidation, children, atherosclerosis