Oxidative Metabolism of 13C Medium chain triglycerid (MCT) in Preterm infants (PT)

Fat Malabsorption in PT infants improves when part of milk fat is replaced by MCT ; Whether these MCT are stored or oxidized is not well known. 5 PT (BW:1771± 100g;GA= 34± 1WKS,Age at study=24±4d)orally fed a formula containing 50% of fat as MCT were given a known amount of 13C trioctanoin on the second day of a 3 day nutrient balance. Continuous indirect calorimetry was performed during the 24 hours following 13C MCT ingestion, with continuous sampling of expired CO2 for measurement of 13C/12C ratio. Energy balance, nutrients oxidation and amount of oxidized MCT were then derived.Preliminary results : 1) Nutrient balances are shown in Table (kg/d ; M±SD)2) Elimination curves of 13C in expired CO2 were of similar pattern but of widely different amplitude. Mean MCT oxidation was 21±12% (range 6-43) and represented 31% (range 7-47%) of the total fat oxidation.Conclusions : 13C CO2 elimination shows considerable variations between PT infants.No correlation is observed with energy expenditure and with total fat oxidation.The later was even lower than the total amount of MCT given.