Plasma amino acid concentrations in children receiving long-term parenteral nutrition

Plasma amino acid concentrations were measured in 15 children aged 4-65 months who received home parenteral nutrition (PN) and in 10 normal controls. In seven patients (Group I), PN was the only source of nutrition. Eight patients (Group II) ingested 30%-70% of their total energy requirements and received the remainder intravenously. Group I and Group II patients received PN for 25.6 +/- 14.4 (SD) and 25.7 +/- 19.1 months, respectively. In comparison to controls, Group I had significantly decreased plasma concentrations of total essential amino acids, the three branched chain amino acids, cystine, tyrosine, and the three major urea cycle amino acids. Group II children displayed decreased plasma concentrations of two branched chain amino acids, leucine and valine, as well as cystine and tyrosine. Taurine was decreased in both groups. The presence of liver disease did not have a major effect on amino acid levels. These data indicate that children receiving long-term parenteral nutrition will develop abnormalities in their plasma amino acid concentrations even though they appear to receive adequate amounts of amino acids in their intravenous solutions. Further studies will be necessary to assess whether modifying the intravenous intake of amino acids will normalize plasma amino acid concentrations in these children.