Plasma and urine amino acid pattern in preterm infants on enteral nutrition: impact of gestational age

Abstract

Plasma and urine amino acids were determined by ion-exchange chromatography in 80 healthy preterm infants divided into three groups: (1) 23 0/7-28 0/7, (2) 28 1/7-32 0/7 and (3) 32 1/7-35 0/7 weeks of gestation. Samples were collected from days 5 to 57 of life, when infants were exclusively orally fed. Infants with evidence of underlying diseases were excluded. Concentrations of most plasma amino acids increased with gestational and maturational age; urinary excretion followed an opposite course. Few amino acids depended on postnatal age. Plasma amino acids did not correlate inversely to their counterparts in urine indicating that plasma amino acids do not simply reflect kidney function. Some amino acids in blood and urine were linked to nutrient intake and body weight. Our data clearly indicate the heterogeneity of the preterm cohort; therefore, gestational age-matched reference values have to be used for diagnostic purposes in preterm infants.

Quantitative urine amino acid analysis using liquid chromatography tandem mass spectrometry and aTRAQ® reagents

“…in childhood likely reflects dietary changes. These overall trends in amino acid concentrations as well as the specific reference intervals are comparable with previously published reference data [9][10][11][12][13].…”

Evaluation of Physiological Amino Acids Profiling by Tandem Mass Spectrometry

“…As previously described (Illsinger et al 2010), large variations in amino acid concentrations are observed in urine of newborns, reflecting the variability of renal tubular function in the first months of life (Rossi et al 1994). …”

Glutamate Promotes Contraction of the Rat Ductus Arteriosus

“…In the enterally fed healthy preterm human infants, the glutamate concentration was similar between preterm, very preterm, and extremely preterm human infants, 37 while previous studies demonstrated a change in aminogram results in disease conditions. 38, 39 Oladipo et al reported that the plasma glutamate level was lower in neonates who were receiving intensive care and who had a diagnosis that included sepsis, day 2, plasma glutamate concentration was, however, lower in extremely preterm infants with PDA than in extremely preterm infants without PDA and more mature preterm infants ( Table 3).…”