Background and Introduction We have previously shown that improving early protein intake is associated with a reduction in insulin-treated hyperglycaemia in preterm infants <29 weeks gestation. The effect of amino acids (AA) on insulin secretion is well described in preterm infants with arginine recognised as a potent secretagogue. We hypothesised that low arginine levels would be associated with an increase in insulin-treated hyperglycaemia and higher mean daily blood glucose levels (day1–15) in infants born <29 weeks gestation.

Methods We performed a secondary analysis on previous randomised controlled trial data comparing hyperalimentation (H) and control (C) regimens. The hyperalimentation regimen provided 20% more carbohydrate than the control regimen. Daily carbohydrate and protein intake data and mean daily blood glucose and insulin use data from the first 15 days of life were substratified according to high (highARG) or low (lowARG) arginine levels on day 8–10 using a reference population based median plasma level (57micromol/l).

Results In group C, substratification identified 41 lowARG and 19 highARG infants. There were no differences in basic demographic factors, carbohydrate or protein intake. Hyperglycaemia peaked on day 5–10. Low arginine levels were associated higher mean daily blood glucose levels (day 6–10) and more insulin treatment (Table 1; group C). In group H, substratification identified 33 lowARG and 22 highARG infants. LowARG infants were of lower gestation and birthweight (p <0.01) There were no differences in carbohydrate or protein intake. Low arginine levels were associated higher mean daily blood glucose levels (day 1–5, 6–10) and more insulin treatment (Table 1; group H).

Conclusion Low plasma arginine levels in very preterm infants are associated with poorer blood glucose control.