[Dietary antioxidants and total antioxidant status in children with nephrotic syndrome]

Several studies indicate the pathophysiological importance of reactive oxygen species in patients with nephrotic syndrome (NS). The present study was designed to determine the effect of dietary antioxidants on antioxidant enzymes (SOD, GPX, GR) activity and on total antioxidant status (TAS) in children with nephrotic syndrome. 36 children with NS (19 with first episode and 17 with relapse of NS) aged 4-16 were included into the study. Total antioxidant status was estimated using two-reagent Randox Total Antioxidant Status test in plasma. All patients had normal blood pressure, normal serum creatinine level and ingested a diet appropriate for age (with individual differences). Total antioxidant status was estimated using two-reagent Randox Total Antioxidant Status test in the plasma. Glutathione peroxidase (GPX), superperoxide dysmutase (SOD) and glutathione reductase (GR) activity was using antioxidant kits (Randox). A 3-day dietary intake record was obtained from each patient and then analyzed with computer program FOOD 2.0. Laboratory investigations were performed before steroid treatment.

1) in children with NS TAS was significantly reduced comparing to controls (0.84 +/- 0.14, 1.21 +/- 0.62 mmol/l, p = 0.002), 2) low manganese intake was found to have negative influence on TAS (TAS = 0.38 + 14.252*Mn, p > 0.001). 3) low intake of all components of antioxidant system was found: zinc (5.6 +/- 3.5 mg/kg b.w./24 h vs 8.6 +/- 4.0 mg/kg b.w./24 h), copper (0.021 +/- 0.013 mg/kg b.w./24 h vs 0.044 +/- 0.014 mg/kg b.w./24 h), manganese (0.029 +/- 0.0021 mg/kg b.w./24 h vs. 0.067 +/- 0.023 mg/kg b.w./24 h), vitamin E (0.15 +/- 0.04 mg/kg b.w./24 h vs 0.26 +/- 0.06 mg/kg b.w./24 h) and vitamin C (0.34 +/- 0.17 mg/kg b.w./24 h vs 0.87 +/- 0.19 mg/kg b.w./24 h).

In children with NS reduced antioxidant protection maybe partly associated with low intake of some vital components of the antioxidant system.