Growth and nitrogen balance in preterm infants fed formula with long chainpolyunsaturated fatty acids

A decrease in nitrogen retention and growth rate has been observed in some formulas supplemented with LCP. In the present study we report on the growt h and nitrogen balance of preterm infants fed formula supplemented with or without a blend of LCP containing both omega-3 and omega-6 fatty acids. A p rospective study was conducted on 58 VLBW-infants with a mean +/- SEM weigh t of 1245+/-21g. The infants were divided into 3 groups. If the mother had milk, the infant received human milk fortified (18 infants). If the mother had no milk, the infant received one of two identical formulas except for t he fat component in a double-blind manner (20 infants each group). Infants were followed up for 30 days on their diets. Initial and final anthropometr ic parameters, BUN, total protein, and albumin were normal and similar in t he three groups. Both, protein intake and protein excretion through urine a nd feces, were similar for the three groups. Mean percent protein absorptio n was 71%. Plasma amino acid levels were similar at the beginning of the st udy and after 30 days were similar for the infants fed the two formulas. Th e infants that received fortified human milk presented significantly higher proline levels and significantly lower lysine, aspartic acid, threonine, g lutamic acid, and methionine levels compared to the infants fed the two for mulas. We conclude that the addition of LCP to preterm infant formula did n ot affect protein absorption or plasma amino acid profile. The formulas did not mimic fully the amino acid profile of preterm infants fed enriched hum an milk. (C) 1999 Elsevier Science Inc.