Extensive and partial protein hydrolysate preterm formulas: The effect on growth rate, protein metabolism indices, and plasma amino acid concentrations

Background: The use of protein hydrolysate preterm formulas is restricted b ecause data on their nutritional adequacy are scarce. The authors evaluated the rate of growth and indices of protein metabolism in low-birth weight i nfants fed extensive and partial protein hydrolysate preterm formula follow ed for 12 weeks. Methods: A total of 61 low-birth weight infants were assigned randomly to r eceive extensive protein hydrolysate preterm formula (EH; n = 16), partial protein hydrolysate preterm formula (PH; n = 15), and standard preterm form ula (SF, n = 15), or were fed their own mother's fortified breast milk (FBM ; n = 15). The infants were investigated at study entry, and at 4, 8, and 1 2 weeks after study entry. Results: There were no differences with respect to growth rate (weight gain , increments in length and head circumference), urea. albumin, prealbumin, transferrin, and plasma amino acid concentrations (except for tyrosine on a single occasion) according to the degree of hydrolysis. There were also no differences between groups fed hydrolyzed formulas and SF. However, severa l differences were found when EH and PH were compared with FBM. Weight gain from the entry to 12 weeks, serum urea at 12 weeks, and total plasma essen tial amino acids at 8 weeks were significantly higher in groups fed EH and PH than in those fed FBM. In addition, valine was significantly higher in g roups fed PH (P < 0.05) than in the group fed FBM at 8 and 12 weeks, tyrosi ne was higher in EH and PH in comparison with FBM at 4 weeks, and in PH ver sus FBM at 12 weeks after study entry. Conclusions: This study suggests that experimental EH and PH are at least n utritionally equivalent to SFs.