PERSISTENT GLUCOSE-PRODUCTION AND GREATER PERIPHERAL SENSITIVITY TO INSULIN IN THE NEONATE VS THE ADULT

Insulin resistance has been reported to partially explain the clinical appearance of neonatal hyperglycemia. To determine the relative resis tance to insulin of glucose production vs. glucose utilization, the eu glycemic hyperinsulinemic damp technique was employed for the first ti me in the human neonate and was combined with stable isotopic determin ation of glucose production and glucose utilization. The basal rates o f glucose production and glucose utilization mere determined, after wh ich each neonate was clamped at his or her own euglycemic glucose conc entration while receiving regular human insulin at one rate of 0.2, 0. 5, 1.0, 2.0, or 4.0 mU . kg(-1) . min(-1). Persistent glucose producti on (greater than or equal to 1 mg . kg(-1) . min(-1)) during the clamp was recorded for all groups. A significant increase in the glucose in fusion rate (P < 0.001) and in percent glucose utilization (P < 0.01) occurred in the 2.0 and 4.0 mU . kg(-1) . min(-1) insulin groups. Meta bolic clearance rate of insulin was significantly greater in the neona te compared with the adult at the 2.0 mU . kg(-1) . min(-1) insulin in fusion rate (P = 0.036). Our results indicate that, in contrast to the adult, the neonate has persistent glucose production (P = 0.001) and greater peripheral sensitivity to insulin (P = 0.015).