Background: Small glycogen stores make very preterm infants more dependent on gluconeogenesis. The magnitude of gluconeogenesis under various clinical conditions in extremely low birth weight infants is unknown.

Aim: Estimate gluconeogenesis in very preterm infants receiving parenteral nutrition with a reduced glucose content aimed at preventing hyperglycemia.

Subjects: 14 infants, 27±1 (mean±SD) gestational wks, 1019±121 g birth weight received glucose 3.0, lipid 1.8 and amino acids 2.2 mg/kg min on day 5±1 of life.

Methods: Gluconeogenesis was determined by mass isotopomer distribution analysis during a 10 Hrs infusion of [U-13C]glucose or[2-13C] glycerol.

Results: During study, plasma glucose was 55±8; glucose Ra was 5.0±0.7 mg/kg min and hepatic glucose production was 2.0±0.7 mg/kg min. Table

Table 1
Full size table

Conclusions: During TPN gluconeogenesis accounts for 1/4 - 1/3 of glucose Ra after 8-10 Hrs of reduced glucose supply.