Oxidative stress and hematologic and biochemical parameters in individuals with Down syndrome.

Objective: To evaluate the levels of thiobarbituric acid reactive substances (TBARS), uric acid, and seric superoxide dismutase and catalase activities, as well as total serum iron, total iron-binding capacity (TIBC), erythrocyte osmotic fragility, and hemograms in people with Down syndrome.

Participants And Methods: The study sampled (July to December 2003) 50 people with Down syndrome and 50 individuals without Down syndrome (control group) matched by age and sex. The levels of TBARS were measured by the TBARS method. Serum superoxide dismutase and catalase activities and uric acid levels were determined spectrophotometrically. Erythrocyte osmotic fragility was assessed by the percentage of hemolysis. Hemograms, total serum iron level, and TIBC were determined with automated systems.

Results: The results showed that levels of TBARS, uric acid, and seric superoxide dismutase and catalase activities were higher in the Down syndrome group compared with the control group. We also observed a slight increase in erythrocyte osmotic fragility in the Down syndrome group, but the total serum iron levels, TIBC, and hemograms for both groups were within the age-related reference values.

Conclusion: This was the first time, to our knowledge, that increases in seric superoxide dismutase and catalase activities were observed in people with Down syndrome. Although other studies are necessary, our results add to the understanding of the mechanisms responsible for the increased oxidative stress observed in individuals with Down syndrome and may be useful in supporting future antioxidant therapies that will improve the lives of people with Down syndrome.