Neonatal hyperglycaemia increases mortality and morbidity in preterm lambs

Hyperglycaemic preterm babies suffer increased mortality and morbidity, but it is not known if these associations are causal or if treatment with insulin improves outcome.

We aimed to investigate the effect of neonatal hyperglycaemia, and its treatment with insulin, on mortality and morbidity in preterm lambs.

Preterm lambs (137 days' gestation; term = 148 days) were randomised to a 12-day intravenous infusion of saline (PremC; n = 39), 50% dextrose (HYPER; n = 47), or 50% dextrose + insulin (INS; n = 21). Term controls (TermC; n = 19) received saline. Dextrose and insulin infusions were titrated to maintain blood glucose concentrations (BGC) at 10-12 mmol·l(-1) (HYPER) or 4-6 mmol·l(-1) (INS).

HYPER lambs had higher BGC (mean (SEM); TermC: 5.6 (0.1), PremC: 5.5 (0.1), HYPER: 10.8 (0.6), INS: 6.2 (0.3) mmol·l(-1); p < 0.0001), higher mortality (n (%); TermC: 0, PremC: 2 (5), HYPER: 11 (23), INS: 0; p < 0.001), higher incidence of fever (n (%); TermC: 3 (16), PremC: 13 (33), HYPER: 26 (55), INS: 6 (29); p = 0.01) and lower weight gain (mean (SEM); TermC: 45.9 (2.9), PremC: 44.2 (2.1), HYPER: 28.4 (1.9), INS: 28.7 (2.8) g·kg(-1)·day(-1); p < 0.0001).

Neonatal hyperglycaemia in preterm lambs causes increased mortality and morbidity, and decreases growth. Insulin treatment to restore euglycaemia attenuated the increased mortality and morbidity, but not the decreased growth.