Glutathione peroxidase activity, lipid peroxides and selenium status in blood in patients with Down's syndrome.

The concentrations of selenium and lipid peroxides and the catalytic activity of glutathione peroxidase were measured in the blood of 6 children (6-16 years of age) and 8 adults (17-27 years old) with Down's syndrome (trisomy 21). The values were compared with those for a control group of age-matched normal people. The selenium concentration in whole blood, erythrocytes and plasma was significantly lower in trisomy 21 patients than in normal subjects (p less than 0.001) in both age groups. No statistically significant differences were observed in selenium concentration in whole blood, erythrocytes and plasma between children and adults in the Down's syndrome group. Glutathione peroxidase catalytic activity in erythrocytes was significantly higher in Down's syndrome children than in healthy children (p less than 0.001). Plasma glutathione peroxidase catalytic activity in both investigated age groups was statistically considerably lower in the Down's syndrome patient group. The concentration of lipid peroxides, expressed as the malondialdehyde concentration, is lower in Down's syndrome patients. No correlation between selenium concentration, glutathione peroxidase catalytic activity and amount of lipid peroxides was found in the trisomy 21 patient group.