In vivo Measurements of Glucose Absorption in Preterm Infants

Abstract

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 μmol/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. K_m and V_max were related to postnatal age. K_m was correlated inversely with the percentage of feedings received as human milk. Antenatal administration of glucocorticoids appeared to increase V_max. 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.

Glucagon-like peptide 2 has limited efficacy to increase nutrient absorption in fetal and preterm pigs

“…Corresponding with this, rates of glucose uptake by intact tissues, BBMV, SGLT-1 mRNA abundance, and glucose uptake capacities of the entire small intestine for preterm pigs exceeded corresponding values for fetuses. The impaired glucose absorption typical of preterm infants (16,23) has led to the consideration that maturation of the pig intestine during the final 10% of gestation is comparable to what occurs during the third trimester of human fetal development (20,21). The present findings provide additional evidence of the complex interactions that exist among the genetic determinants and signaling molecules that drive perinatal intestinal development.…”

“…THE IMMATURE SMALL INTESTINE of premature infants has underdeveloped capacities to absorb monosaccharides, which increases the risks for malabsorption and infections (16,23). As a consequence, parenteral nutrition [total parenteral nutrition (TPN)] is initially used for some preterm neonates before enteral nutrients are provided.…”

Early postnatal nutrition and programming of the preterm neonate

“…A further contribution is limitations in the ability of the preterm infant to absorb nutrients 15–17 . Nutrient absorption for the preterm infant could be decreased because of the preterm infant's underdeveloped gastrointestinal tract and accompanying microflora.…”

Carbohydrate maldigestion induces necrotizing enterocolitis in preterm pigs

“…Instead, they receive parenteral nutrition, which may further delay or reduce the maturation of digestive enzymes. Studies in premature infants demonstrate that lactose digestion and glucose absorption increase with gestational age but that some degree of lactose malabsorption and colonic fermentation still occurs (23,43,45,46). Although colonic fermentation of lactose is accompanied by an increase in gas production, there is no clear evidence that this phenomenon induces NEC in infants (23).…”