Leucine metabolism in preterm infants receiving parenteral nutrition with medium-chain compared with long-chain triacylglycerol emulsions.
Am J Clin Nutr
; 69(3): 539-43, 1999 Mar.
Article
em En
| MEDLINE
| ID: mdl-10075342
ABSTRACT
BACKGROUND:
Although medium-chain triacylglycerols (MCTs) may be utilized more efficiently than long-chain triacylglycerols (LCTs), their effect on protein metabolism remains controversial.OBJECTIVE:
The aim of the study was to compare the effects of mixed MCT-LCT and pure LCT emulsions on leucine metabolism in preterm infants.DESIGN:
Fourteen preterm [gestational age 30+/-1 wk; birth weight 1409+/-78 g (x +/- SE)] neonates were randomly assigned to receive, from the first day of life, either a 5050 MCT-LCT (mixed MCT group; n = 7) or an LCT (LCT group; n = 7) lipid emulsion as part of an isonitrogenous, isoenergetic total parenteral nutrition program. On the fourth day, infants received intravenous feeding providing 3 g lipid, 15 g glucose, and 3 g amino acids kg(-1) x d(-1) and underwent 1) indirect calorimetry and 2) a primed, 2-h infusion of H13CO3Na to assess the recovery of 13C in breath, immediately followed by 3) a 3-h infusion of L-[1-13C]leucine.RESULTS:
The respiratory quotient tended to be slightly but not significantly higher in the mixed MCT than in the LCT group (0.96+/-0.06 compared with 0.93+/-0.03). We did not detect a significant difference between the mixed MCT and LCT groups with regard to release of leucine from protein breakdown (B; 309+/-40 compared with 257+/-46 micromol x kg(-1) x h(-1)) and nonoxidative leucine disposal (NOLD; 296+/-36 compared with 285+/-49 micromol x kg(-1) x h(-1)). In contrast, leucine oxidation was greater in the mixed MCT than in the LCT group (113+/-10 compared with 67+/-10 micromol x kg(-1) x h(-1); P = 0.007). Net leucine balance (NOLD - B) was less positive in the mixed MCT than in the LCT group (-14+/-9 compared with 28+/-10 micromol x kg(-1) x h(-1); P = 0.011).CONCLUSION:
Mixed MCTs may not be as effective as LCT-containing emulsions in promoting protein accretion in parenterally fed preterm neonates.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Triglicerídeos
/
Recém-Nascido Prematuro
/
Nutrição Parenteral
/
Alimentos Infantis
/
Leucina
Tipo de estudo:
Clinical_trials
Limite:
Humans
/
Newborn
Idioma:
En
Ano de publicação:
1999
Tipo de documento:
Article