Attenuated Response to Insulin in Very Low Birthweight Infants

Abstract

Summary: Four hyperglycemia very low birthweight (VLBW) infants were given a constant infusion of insulin with parenteral alimentation in order to improve glucose tolerance. After an initial 45% decrease in serum glucose, intolerance recurred within hours to days despite delivery of as much as 16 units/kg/hour of regular insulin. Resulting serum insulin levels were as high as 72,000 μU/ml. It is suggested that insulin “resistance”, instead of insulin deficiency, may be responsible for glucose intolerance in some infants. Speculation: Abnormal hepatic regulatory systems, immature enzyme systems, or abnormal insulin receptors may play a part in the glucose intolerance of the premature infant. Further studies, both in human infants and in appropriate animal models will have to be done to determine the etiology (ies) of the glucose intolerance.