The Effects of Human Milk and Low-Protein Formulae on the Rates of Total Body Protein Turnover and Urinary 3-Methyl-Histidine Excretion of Preterm Infants

Publisher Website
Google Scholar
Abstract
The effects of human milk and 2 low-protein formulae on the protein metabolism of 30 preterm appropriate for gestational age infants, birth weight 1.5-2.0 kg, were studied. The compositions of the 2 formulae were identical except for the protein source, with either casein or whey predominant. The 3 diet groups all received similar N (390 mg of N day-1 kg-1) and energy intakes (500 kJ day-1 kg-1). Growth rates for length and weight were comparable and approximated to intrauterine growth. N absorption and net N utilization were enhanced in the human-milk-fed group. There were no differences in N retention, which averaged 274 mg day-1 kg-1 and approximated to intrauterine accretion rates. Rates of whole-body N flux, protein synthesis and breakdown in the human-milk group were increased by 43-54% over the values seen in either of the 2 formula-fed groups (P < 0.01). No differences were seen between the 2 formula groups. No differences were seen in urine 3-methylhistidine excretion between the 3 study groups. Significant differences in the whole-body protein metabolism of formula-fed infants compared with human-milk-fed infants are suggested.