Glucose Metabolism, Plasma Insulin, and Growth Hormone Secretion in Newborn Infants With Erythroblastosis Fetalis Compared With Normal Newborns and Those Born to Diabetic Mothers

Abstract

Twenty-two erythroblastotic infants (IEF), 22 normal infants, and 12 infants of diabetic mothers (IDM) were studied during their first day of life. Blood glucose, plasma insulin, and growth hormone were measured in the first 90 minutes after I-V glucose injection (1 gm/kg). Mean fasting blood glucose of normal infants was significantly higher than that of IDMs. In four IEF, blood glucose levels lower than 20 mg/100 ml were observed. No significant difference of glucose tolerance (Kt) was found among the three groups of babies. The mean fasting plasma insulin level in IDMs was significantly higher than in control infants and in IEF. In the IEF a significant correlation was found (A) between hemoglobin (Hb) and Kt values, (B) between Hb and fasting plasma insulin. (C) between fasting blood glucose and fasting plasma insulin, and (D) between Kt and the sum of plasma insulin levels 3, 5, and 10 minutes after I-V glucose. All normal babies and sixteen IEF showed a double course of insulin response. IDM showed a nearly monophasic pattern, but with a secondary minor peak between 30 and 60 minutes in some. In six (four with hypoglycemia) of the IEF group a single peak response of plasma insulin was found, together with mean Kt and fasting plasma insulin values higher than those of control infants. Fasting mean HGH concentration in plasma showed no significant difference among the groups of infants. During intravenous glucose tolerance tests mean values in IDM significantly higher than in normal infants and in IEF were found at 90 minutes.