Influence of age on activities of antioxidant enzymes and lipid peroxidation products in erythrocytes and neutrophils of Down syndrome patients

Thirty-seven individuals with Down syndrome (DS) were divided into four age categories: i) 1 to < 6 years, (ii) 6 to < 13 years, (iii) 13 to < 20 year s, and (iv) over 20 years. Activities of antioxidant enzymes found in indiv idual age categories were different, but the differences between age groups were not statistically significant. We confirmed significantly higher acti vities of Cu/Zn superoxide dismutase (SOD) and glutathione peroxidase (GPx) in blood cells of people with DS as compared to 35 controls, which consist ed, for the first time, of siblings of children with DS. No significant dif ferences were found in activities of catalase and glutathione reductase in DS vs. controls. A significant difference was observed in serum concentrati on of malondialdehyde (MDA) in DS vs. controls (8.39 +/- 0.34 <mu>mol/l vs. 7.34 +/- 0.27 mu mol/l; p =.021) and concentration of MDA in erythrocytes of individuals with DS between the third and fourth age group (p =.05). In DS persons, an elevated ratio of SOD to catalase plus GPx with respect to t he controls in all age categories was found, suggesting oxidative imbalance , potentially contributing to accelerated aging observed in these persons. (C) 2001 Elsevier Science Inc.