Selenium in Plasma and Erythrocytes in Patients with Down's Syndrome and Healthy Controls

ABSTRACT. The mean plasma selenium concentration (P-Se) in 65 patients with Down's syndrome (DS) did not differ from that in 90 healthy controls. The concentration of selenium in the erythrocytes (E-Se) was higher in DS patients than in controls ( p <0.001). P-Se and E-Se increased progressively with age through childhood in both DS children and controls. The former children, however, started out with higher levels of E-Se and reached adult concentrations earlier (at 7-17 years) than controls (18 years). Adult DS patients and controls did not differ in their mean P-Se or E-Se concentration. There was a significant correlation between P-Se and E-Se both in DS patients and in controls. In DS patients each of these two variables was significantly correlated to glutathione peroxidase (GSH-Px) activity in erythrocytes. A sex difference in the DS children, but not in the controls, was observed with regard to P-Se and E-Se levels, these being higher in DS girls during childhood (0-17 years). This was in accordance with an earlier finding of higher GSH-Px activity in DS girls than in DS boys.