Effect of low versus high early parenteral nutrition on plasma amino acid profiles in very low birth-weight infants

Objective: To study the efficacy of early high doses parenteral nutrition (PN) versus early low dose with progressive increments PN regimens, we performed a prospective randomized study in very low birth-weight infants. Study design: Forty-one appropriate gestational age preterm infants with birth weights ranging from 750-1500 g were randomly assigned into two groups. In Group 1, infants started on 3.0 g/kg/day amino acids (AA) and 3 g/kg/day of 20% lipid; in Group 2, AA and lipid were started on 1 g/kg/day, and advanced over 3 days to a maximum 3 g/kg/day. Blood samples were obtained for AA concentrations before starting of the PN, and at the 7th and 14th days. Results: The mean (+/-SD) birth weight was 1335 g (240), gestational age was 29.7 weeks (1.7) of the study group. The mean body weight and head circumference was similar in the Group 1 and Group 2 at the 14th postnatal days. There was no difference in the blood levels of triglyceride, blood urea nitrogen, creatinine, ammonia, lactat and bicarbonate in the two groups. There was no significant difference in the concentrations of AA except for arginine and asparagine. On day 14, the mean arginine concentrations were significantly higher and asparagine concentrations were lower in Group 2. Conclusion: Although earlier more aggressive administration of AA and fat is not associated with any significant metabolic abnormalities, growth rates and plasma AA concentrations of the infants were similar to infants who AA and lipid given lower in the first day of life.