Inflammatory response in preterm infants is induced early in life by oxygen and modulated by total parenteral nutrition

Abstract

The i.v. lipid emulsion (LIP) is a source of oxidants, which may stimulate inflammation. Coadministration of parenteral multivitamins (MVP) with LIP prevents lipid peroxidation in light-exposed total parenteral nutrition (TPN). We hypothesized that this modality of TPN administration affects systemic inflammation, which may be modulated by exposure to oxygen. Premature infants were allocated to three TPN regimens: control regimen - MVP coadministered with amino acid/dextrose exposed to ambient light, LIP provided separately (n = 9) - LIP+MVP light exposed (LE): MVP coadministered with light-exposed LIP (n = 9) - LIP+MVP light protected (LP): MVP coadministered with light-protected LIP (n = 8). In LE and LP, amino acid/dextrose was provided separately. On reaching full TPN, infants were sampled for IL-6 and IL-8 in plasma and the redox potential of glutathione in whole blood (E, mV). Data were compared (ANOVA) in infants exposed to low (<0.25) versus high (> or =0.25) FiO2. Patients (mean +/- SD: birth weight 797 +/- 172 g; GA 26 +/- 1 wk) had similar clinical characteristics in TPN groups. Cytokine levels correlated positively (p < 0.01) with FiO2 and E. High FiO2 stimulated an increase (p < 0.01) in cytokines in control regimen, whereas these markers remained unaffected by oxygen in the LE and LP groups. The choice of a TPN admixture may have important consequences on the systemic inflammatory response triggered by an oxidant stress.

Figure 1

Plasma levels of IL-6 and IL-8 in preterm infants receiving TPN. Preterm infants were allocated to receive one of the following TPN regimens: AA, multivitamin (MVP) +amino acid/dextrose solution with lipid (LIP) provided separately (n = 9); LE, MVP administered with LIP exposed to light with amino acid/dextrose solutions provided separately (n = 9); LP, MVP administered with LIP protected from light with amino acid/dextrose solutions provided separately (n = 8). IL-6 (left panel) and IL-8 (right panel) were measured from plasma sampled on 7th day of life (● sample 1) and 10th day of life (○ sample 2). Data (mean ±SD) were compared by ANOVA between infants (n = sample 1; sample 2) exposed to low (<0.25) vs high (≥ 0.25) FiO₂; *p < 0.05.