Plasma fatty acids, human milk fortification and lipid oxidation in premature infants

Abstract

Human milk fortifiers (HMF) are routinely added to mother's milk (HM) for the premature infant. We reported data on 65 premature infants (birth weight < 1500 g) who were either fed HM with varying levels of HMF or formula (F) while they were in hospital receiving oral feeds. A significant increase (P<0.05) in urine_F2‐isoprostanes was found as HMF supplementation increased (Pediatr Res. 2011 Feb; 69(2): 160–4). Isoprostanes are prostaglandin‐like compounds formed in vivo from the free radical‐catalyzed peroxidation of essential fatty acids primarily arachidonic acid (AA C20:4n6). Linoleic acid (LA 18:2n6) is a polyunsaturated fatty acid used in the biosynthesis of AA. LA in HM ranges from 7 to 24 % of total fatty acids. LA in HMF is 140 mg per packet. We hypothesized that premature infants who had higher (n=7, providing total samples 20) F2 isoprostanes in urine would have more LA in their plasma from BM + HMF than those who were lower (n=10, providing total samples 31). Plasma samples from infants at bi‐weekly visits were analyzed for total fatty acids by standard assay using GS‐FID and heptadecanoic acid as the internal marker. Results (%w/w) were: High; LA 21.3 + 1.6 vs low 23.8 + 0.8, P < 0.05) and AA: High; 6.5 + 0.3 vs Low 6.8 + 0.4 NS). The hypothesis is not supported and suggests that other reasons exist for elevated isoprostanes in premature infants fed HMF than plasma lipid levels. Supported by CIHR and MICH