Objectives: To evaluate the effect of trace elements (TEs), when added to total parenteral nutrition (TPN) solutions, on peroxides load, and to test the hypothesis that protection of TPN from light can decrease peroxides load and is associated with improvement in oxidant-related clinical outcomes in preterm infants.
Subjects and methods: A total of 80 preterm infants were randomized to 1 of 4 groups (n=20 each): group 1 received a mixture of dextrose and amino acids; group 2 received a mixture of dextrose, amino acids, and lipid emulsion; group 3 received dextrose, amino acids, lipid emulsion, and multivitamins (MVP); and group 4 received dextrose, amino acids, lipid emulsion, MVP, and TEs. Each group was subdivided into photo-protected and photo-exposed subgroups (n=10 each). Using ferrous oxidation of xylenol orange technique, we measured the baseline level of excreted urinary peroxides before and 48 hours after starting TPN. We examined the association among light protection, urinary peroxides, and clinical outcomes of these infants.
Results: Baseline urinary peroxides ranged between 5.5 and 24.8 micromol/L. A significant increase in urinary peroxides was observed in all groups after receiving TPN. The use of TEs did not affect peroxide production. In regression analysis, the addition of MVP (P<0.0001) and the exposure to light (P=0.02) were significantly associated with increased urinary peroxides. In the overall population, light exposure was associated with a significant increase in the incidence of chronic lung disease (adjusted OR 9.26, confidence interval 1.2-73; P=0.03) but had no effect on mortality, necrotizing enterocolitis, or sepsis.
Conclusions: TEs in TPN solutions have no effect on the production of urinary peroxides. Addition of MVP and exposure of TPN to light are the 2 major sources of peroxides in TPN. Protection from ambient light is associated with a decrease in chronic lung disease.
Trial registration: ClinicalTrials.gov NCT00611546.