Quantitation of oxidation of medium-chain triglycerides in preterm infants.
Medium-chain triglycerides, with a chain length of eight and 10 carbon atoms, form up to 50% of the total fat content in some preterm infant formulas. In 20 small preterm infants (birthwt: 1153 +/- 227 g; mean +/- SD) fed a special formula containing 40% MCT, a primed constant oral infusion study of 1-13C-potassium octanoate was conducted to quantify the oxidation of MCT. A plateau in 13C enrichment in breath CO2 was reached in all patients within 1-3 h. Simultaneously, substrate utilization was measured using a closed system indirect calorimeter. No significant difference was found between appropriate for gestational age (n = 8) and small for gestational age (n = 12) infants in the percentage of the administered tracer that was oxidized (44.9 +/- 9.1% versus 48.5 +/- 11.0%). In all patients, the recovery was calculated to be 47.1 +/- 10.2%, which is less than previously estimated and corresponds to a mean MCT oxidation of 1.26 +/- 0.27 g/kg/d. With indirect calorimetry, a total fat oxidation of 1.42 +/- 0.84 g/kg/d in appropriate for gestational age and 2.00 +/- 0.85 g/kg/d in small for gestational age infants was found, indicating that MCT accounted for around 85% of the total fat oxidation in appropriate for gestational age versus 65% in small for gestational age infants.
Sulkers
E J
EJ
Department of Paediatrics, Erasmus University, Rotterdam, The Netherlands.
Lafeber
H N
HN
Sauer
P J
PJ
D001944:Breath Tests; D002153:Calorimetry, Indirect; D002210:Caprylates / Q000008:administration & dosage / Q000378:metabolism*; D002247:Carbon Isotopes; D002149:Energy Intake; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D007236:Infant, Small for Gestational Age / Q000378:metabolism; D010084:Oxidation-Reduction; D014280:Triglycerides / Q000008:administration & dosage / Q000378:metabolism*
D002210:Caprylates; D002247:Carbon Isotopes; D014280:Triglycerides; C031492:octanoic acid