Blood glucose, plasma insulin, and free fatty acid interrelationships were examined in newborn infants during and after continuous hourly glucose infusions at rates varying from 4 to 24 mg/kg/minute. Normal newborn infants disposed of glucose efficiently until glucose was infused at rates greater than 6 mg/kg/minute. Plasma insulin levels rose gradually during glucose infusion. When large loads of glucose infusion were initiated (12 mg/kg/minute), however, there was a delay in plasma insulin rise.
At the slow rates of glucose infusion, the infants of gestational or insulin-dependent diabetic mothers disposed of the exogenous glucose more slowly than the normal newborns. Plasma insulin levels in the infants of gestational diabetic mothers were similar to those in the normal infants. These observations suggest that, with comparable glucose stimulus by continuous infusion, the infants of diabetic mothers do not have excessive insulin output.
Salivary insulin concentrations in Type 2 (non-insulin-dependent) diabetic patients and obese non-diabetic subjects: Relationship to changes in plasma insulin levels after an oral glucose load