Increased urinary peroxides in newborn infants receiving parenteral nutrition exposed to light

Objectives: To determine whether peroxide loads infused with total parenter al nutrition (TPN) are fully quenched by premature infants. Study design: After baseline urine peroxide levels were established, the ef fect of various parenteral regimens was correlated with urinary peroxide le vels in 64 newborn infants less than or equal to 32 weeks' gestation. This correlation was achieved with the properties of light and of various parent eral nutrient admixtures on the generation of peroxides. Peroxides were mea sured by the ferrous oxidation of xylenol orange. Results: The level of urinary peroxides measured for infants given a fat-fr ee TPN regimen unprotected from light (74.5 +/- 15.3 mu mol/L) was similar to levels found in infants given a lipid-containing regimen (88.1 +/- 10.3 mu mol/L). When photoprotected, the fat-free alimentation was associated wi th peroxide levels (28.8 +/- 2.8 mu mol/L) similar to those measured before TPN (27.6 +/- 4.1 mu mol/L). Conclusions: Because urine peroxide levels are changed by various nutrition al procedures, antioxidant systems of premature infants are unable to fully quench the oxidant load associated with TPN.