Glucose Intolerance in Infants of Very Low Birth Weight

Abstract

61 intravenous glucose tolerance tests (GTT) were performed within 24 h of birth in 50 infants of birth weights 500–1,380 g. Glucose exposure prior to the test in 33 of the GTT resulted in higher mean plasma glucoses, more frequent preinfusion hyperglycemia (glucose > 125 mg/100 ml), and a greater proportion of slower glucose disappearance rates (Kt) when compared to the 28 ‘fasting’ infants who received no glucose prior to the test. In seven of the fasting tiny babies, two immediately successive (‘double’) GTT were performed within 8.5 h of birth. Contrary to all previously reported studies in healthy adults and mature newborns, these babies failed to demonstrate an increased rate of glucose disappearance and signifanctly lower plasma glucoses in the initial phase of the second test. These unique findings help explain previous observations from this laboratory of significant hyperglycemia in infants of very low birth weight and further document their vulnerability to hyperglycemia with parenteral glucose infusions.