75 POSTNATAL METABOLIC ADAPTATION – THE EFFECTS OF GESTATION AND FEEDING

Abstract

Gluconeogenesis and ketogenesis are integral aspects of postnatal metabolic adaptation. This study compared the pre-feed metabolic profiles of 156 term and 62 preterm infants, aged 0-6 days,. with those of 52 older children, to examine the effects of gestation and current feeding practices on these processes. Preterm infants had lower mean blood glucose concentrations than term infants in the first few postnatal hours (2.5 mmol/l vs 3.2 mmol/l; P<0.05), and levels of gluconeogenic precursors were high at this time. Unlike term infants and older children, preterm infants had low ketone body concentrations, even when blood glucose concentrations were low. Independently of gestational age, ketone body concentrations of preterm infants were related to intake volume of enteral feed. For term infants, blood glucose concentration was inversely related to between feed interval, breast fed infants had lower blood glucose concentrations than formula fed term infants (3.6 vs 4.0 mmol/l;<P 0.05). Preterm infants appear less able than term infants to utilise gluconeogenic percursors immediately after birth, or mount a ketogenic response during the first postnatal week. Enteral feeding of preterm infants may stimulate maturation of metabolic adaptation.