In vivo measurements of glucose absorption in preterm infants.
Few data are available regarding the kinetics of glucose absorption in the preterm infant. In order to ascertain the kinetics of glucose absorption in the premature infant and how rate of infusion and concentration affect absorption, jejunal glucose absorption kinetics were measured in 16 preterm infants by infusing 1, 10, and 100 mM glucose solutions in random order. Seventeen infants were perfused with glucose (100 micromol/min) by infusing 67 mM glucose at 1.5 ml/min and 133 mM glucose at 0.75 ml/min to determine the effect of changes in rate of infusion vs. concentration on glucose absorption. Km and Vmax were related to postnatal age. Km was correlated inversely with the percentage of feedings received as human milk. Antenatal administration of glucocorticoids appeared to increase Vmax. The higher infusion rate resulted in greater glucose absorption than the higher concentration glucose solution.


CONCLUSIONS
The characteristics of glucose absorption in the preterm infant change with age and are affected by diet, glucocorticoids, and the method of infusion. These data have implications for the feeding of preterm infants.
Shulman
R J
RJ
USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, and Texas Children's Hospital, Houston, Tex. 77030, USA. rschulman@bcm.tmc.edu
D000042:Absorption; D004305:Dose-Response Relationship, Drug; D004750:Enteral Nutrition; D005947:Glucose / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D009994:Osmolar Concentration
D005947:Glucose