13 MATURATION OF THE HORMONAL ENTEROINSULAR AXIS IN NEW-BORN INFANTS OF INSULIN-TREATED DIABETIC MOTHERS

Abstract

To study whether the increased glucose levels in the amniotic fluid during diabetic pregnancies induce an early maturation of the hormonal enteroinsular axis we measured blood glucose (BG) levels and plasma concentrations of C-peptide (CP), pancreatic glucagon, enteroglucagon (EG) and gastric inhibitory polypeptide (GIP) before and after the first feed in 20 newborn infants of diabetic mothers (IDM) and 12 infants of nondiabetic mothers. All infants were given their first feed comprising human milk (5 ml/kg) by a nasogastric tube at the age of 2 hours. Blood samples were taken before and at 5, 30, 60 and 120 minutes after feeding. At the beginning the IDM had significantly lower BG levels, higher CP and lower EG concentrations. There was a significant increase in BG levels in both groups after the feed and 2 hours after feeding the BG concentrations were of the same magnitude in both groups. No significant CP response could be observed in either of the groups but the IDM had significantly higher C-peptide concentrations at all time points studied. A significant EG and GIP response could be seen in the IDM but not in the controls. However, we did not find any significant differences between the two groups in the absolute plasma concentrations of these two hormones. Our results show that enteral feeding with human milk corrects the early postnatal hypoglycemia within 2 hours in most IDM without causing any exacerbation of their hyperinsulinemia. The absence of any differences in the absolute concentrations of GIP and EG in the peripheral circulation after the first feed suggests that the enteroinsular axis matures postnatally in IDM as well as in normal infants.