Plasma arginine levels and blood glucose control in very preterm infants receiving 2 different parenteral nutrition regimens

Abstract

Background: Improving parenteral nutrition (PN) amino acid (AA) intake in very preterm infants is associated with less hyperglycemia. AAs stimulate newborn insulin secretion with arginine, demonstrating a specific effect. We hypothesized that low arginine levels would be associated with increased insulin-treated hyperglycemia and higher mean daily blood glucose levels in very preterm infants.

Methods: We performed a secondary analysis on previous study data comparing high-protein/calorie PN (HPC-PN) and control groups in infants <29 weeks' gestation. Infants were substratified (within original groups) according to high (highARG) and low (lowARG) plasma arginine levels on days 8-10 using a reference population-derived threshold for high/low arginine (57 µmol/L). Daily protein, arginine, carbohydrate intake, mean daily blood glucose, and insulin treatment data from the first 15 days of life were collected.

Results: Control group infants (n = 60) were stratified into lowARG (n = 41) and highARG (n = 19) groups. There were no differences in basic demographic data or carbohydrate intake. LowARG infants had higher mean daily blood glucose levels ( P .05) and a trend to more insulin treatment on days 610. HPC-PN group infants (n = 55) were stratified into lowARG (n = 33) and highARG (n = 22) GROUPS. LowARG infants had lower gestation and birth weight and were sicker than highARG infants. There were no differences in carbohydrate intake. LowARG infants had higher mean daily blood glucose levels (p .01) and more insulin treatment (p .01) on days 15 and 610. Insulin-treated hyperglycemia was also associated with low plasma glutamine levels.

Conclusion: Low plasma arginine levels (≤57 µmol/L) in very preterm infants are associated with poorer blood glucose control.

Keywords: amino acids; arginine; hyperglycemia; insulin; parenteral nutrition; preterm.