Metabolic and clinical consequences of changing from high-glucose to high-fat regimens in parenterally fed newborn infants.
To evaluate the metabolic and clinical consequences of changing from high-glucose to high-fat regimens during initiation of parenteral nutrition, we performed 22 studies in 11 newborn infants (birth weight (mean +/- SD) 2.54 +/- 0.54 kg, gestational age 37 +/- 3 weeks, postnatal age 8 +/- 3 days) maintained in a constant thermal environment. In a paired design, two isoproteinic (2.4 +/- 0.2 gm/kg/day) and isocaloric (64 +/- 6 kcal/kg/day) regimens differing by source of energy (high glucose vs high lipid) were infused on consecutive days. Environmental and body temperatures were recorded during a 4-hour period, and 24-hour urinary excretions of catecholamines, nitrogen, and C peptide were measured. Despite constant incubator and average skin temperatures, the rectal and interscapular temperatures rose significantly when the high-glucose regimen was changed to a high-lipid regimen. The specific locations of these changes in body temperature suggested brown fat activation. A significant drop in nitrogen retention (63 +/- 9% vs 56 +/- 10%) during the lipid infusion could be further evidence of a metabolic adaptation to the rapid change in energy substrates.
Chessex
P
P
Department of Pediatrics, University of Montreal, Quebec, Canada.
Gagne
G
G
Pineault
M
M
Vaucher
J
J
Bisaillon
S
S
Brisson
G
G
D002096:C-Peptide / Q000652:urine; D002395:Catecholamines / Q000652:urine; D004041:Dietary Fats / Q000008:administration & dosage* / Q000378:metabolism; D002149:Energy Intake; D005865:Gestational Age; D005947:Glucose / Q000008:administration & dosage* / Q000378:metabolism; D006801:Humans; D007225:Infant Food; D007231:Infant, Newborn; D009584:Nitrogen / Q000652:urine; D010289:Parenteral Nutrition, Total
D002096:C-Peptide; D002395:Catecholamines; D004041:Dietary Fats; D005947:Glucose; D009584:Nitrogen