Urinary uric acid and antioxidant capacity in children and adults with Down syndrome

ObjectivesTo evaluate the urinary levels of uric acid (UA) and total antioxidant capacity (TAC) with and without UA relative contribution (TAC−UA) in children and adults with Down syndrome (DS) and to prove the clinical use of TAC.Design and methodsUrine samples were obtained from 32 individuals with DS and 29 controls. Two age groups were established (children and adults). Spectrophotometric methods were used for biochemical determinations.ResultsChildren with DS had significantly higher UA/Cr and TAC/Cr levels than controls, whereas levels of TAC−UA/Cr were lower in adults with DS than in controls (P < 0.05 for all). In DS, levels of UA/Cr, TAC/Cr and TAC−UA/Cr were higher in children than in adults (P < 0.05 for all). Positive correlations between UA/Cr and TAC/Cr were found for all groups studied. Negative correlations with age were found for UA/Cr and TAC/Cr in children of both groups.ConclusionsOur results proved that TAC is decreased in adults with DS. Besides, TAC−UA seems to provide more reliable information about the antioxidant status, at least in DS.