Background: The goal of this study was to evaluate the effect of 2 different strategies for parenteral amino acid (AA) supplementation in the range of standard doses (>1.0-1.5 g/kg/d) on growth outcomes in very low birth weight (VLBW) infants.
Materials and methods: The unit policy of AA doses on the first day of life changed from 1.5 g/kg/d (n = 56; standard protein group, SP, in 2008) to 3.0 g/kg/d (n = 53; high protein group, HP, in 2009) with a daily advance to a target dose of 3.5-4.0 g/kg/d. Daily nutritive and laboratory profiles were collected for the initial 14 days, and patient weight, height, and head circumference on postnatal day 14 and again at 36 weeks, 6 months, and 12 months of corrected age were evaluated.
Results: During the first 14 days, AA intake was greater in the HP group than in the SP group (2.9 ± 0.4 vs 2.6 ± 0.4 g/kg/d, P < .001). The HP group demonstrated a lower peak plasma glucose level during the first 3 days (116 ± 24 vs 137 ± 39 mg/dL) and a higher serum urea nitrogen level for the first 14 postnatal days than the SP group (19.2 ± 7.0 vs 14.8 ± 6.7 mg/dL) (both P < .01). From birth to postnatal 14 days and to 36 weeks, 6 months, and 12 months of corrected age, the z score changes in all growth parameters did not differ between the 2 groups.
Conclusion: In the range of the standard AA protocol, there was no dose-response relationship between the early AA doses and the growth outcomes in VLBW infants.