Protein-metabolism kinetics and energy-substrate utilization in infants fed parenteral solutions with different glucose-fat ratios.
The relative effect of glucose and lipids on whole-body protein-metabolism kinetics was assessed in seven infants undergoing parenteral feeding. Protein intake was kept constant and nonprotein energy was either provided as glucose alone or as an isoenergetic glucose-lipid mixture according to a randomized crossover trial. Protein metabolism and energy-substrate utilization were assessed by a primed, constant L-[13C]leucine infusion, combined with indirect calorimetry. There was a significant difference in the pattern of energy-substrate utilization according to regime. Protein turnover (11.3 +/- 0.7 vs 9.8 +/- 0.4 g.kg-1.d-1; P less than 0.05), protein breakdown (8.4 +/- 0.6 vs 7.1 +/- 0.4 g.kg-1.d-1; P less than 0.05), and amino acid oxidation rates (2.7 +/- 0.4 vs 1.4 +/- 0.5 g.kg-1.d-1; P less than 0.05) were higher for the glucose than the glucose-lipid treatment, whereas protein-synthesis rates did not significantly differ. These results suggest that the nature of energy substrates delivered to parenterally fed infants may affect protein metabolism.
Bresson
J L
JL
Département de Pédiatrie, Hôpital des Enfants Malades, Paris, France.
Bader
B
B
Rocchiccioli
F
F
Mariotti
A
A
Ricour
C
C
Sachs
C
C
Rey
J
J
D002153:Calorimetry, Indirect; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005947:Glucose / Q000008:administration & dosage*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007651:Keto Acids / Q000097:blood; D007700:Kinetics; D007930:Leucine / Q000097:blood; D008055:Lipids / Q000008:administration & dosage*; D010288:Parenteral Nutrition; D011506:Proteins / Q000378:metabolism*
D005230:Fatty Acids, Nonesterified; D007651:Keto Acids; D008055:Lipids; D011506:Proteins; C013082:alpha-ketoisocaproic acid; D007930:Leucine; D005947:Glucose