Early insulin therapy in very-low-birth-weight infants. Hyperglycemia in extremely- low-birth-weight infants.
Studies involving adults and children being treated in intensive care units indicate that insulin therapy and glucose control may influence survival. Hyperglycemia in very-low-birth-weight infants is also associated with morbidity and mortality. This international randomized, controlled trial aimed to determine whether early insulin replacement reduced hyperglycemia and affected outcomes in such neonates.
                In this multicenter trial, we assigned 195 infants to continuous infusion of insulin at a dose of 0.05 U per kilogram of body weight per hour with 20% dextrose support and 194 to standard neonatal care on days 1 to 7. The efficacy of glucose control was assessed by continuous glucose monitoring. The primary outcome was mortality at the expected date of delivery. The study was discontinued early because of concerns about futility with regard to the primary outcome and potential harm.
                As compared with infants in the control group, infants in the early-insulin group had lower mean (+/-SD) glucose levels (6.2+/-1.4 vs. 6.7+/-2.2 mmol per liter [112+/-25 vs. 121+/-40 mg per deciliter], P=0.007). Fewer infants in the early-insulin group had hyperglycemia for more than 10% of the first week of life (21% vs. 33%, P=0.008). The early-insulin group had significantly more carbohydrate infused (51+/-13 vs. 43+/-10 kcal per kilogram per day, P<0.001) and less weight loss in the first week (standard-deviation score for change in weight, -0.55+/-0.52 vs. -0.70+/-0.47; P=0.006). More infants in the early-insulin group had episodes of hypoglycemia (defined as a blood glucose level of <2.6 mmol per liter [47 mg per deciliter] for >1 hour) (29% in the early-insulin group vs. 17% in the control group, P=0.005), and the increase in hypoglycemia was significant in infants with birth weights of more than 1 kg. There were no differences in the intention-to-treat analyses for the primary outcome (mortality at the expected date of delivery) and the secondary outcome (morbidity). In the intention-to-treat analysis, mortality at 28 days was higher in the early-insulin group than in the control group (P=0.04).
                Early insulin therapy offers little clinical benefit in very-low-birth-weight infants. It reduces hyperglycemia but may increase hypoglycemia (Current Controlled Trials number, ISRCTN78428828.)
                2008 Massachusetts Medical Society The cause of hyperglycemia in extremely-low-birth-weight (ELBW) infants is not well understood. We studied infants weighing <1,000 g to investigate the relationship of hyperglycemia to blood levels of insulin-like growth factor (IGF)-I and IGF-II. We also compared two methods of treatment for hyperglycemia: continuous insulin infusion and reduction of glucose intake. Fifty-six ELBW infants were enrolled on day 2 of life. Intravenous glucose intake was increased incrementally to a maximum of 12 mg/kg/min on day 6. Infants who developed hyperglycemia were randomly assigned to receive reduced glucose intake (n = 11) or insulin infusion (n = 12). Infants whose blood sugar remained normal served as controls (n = 33). Blood was drawn on days 3, 8 and 15 in all infants, and again when they developed hyperglycemia. Nutritional intake and laboratory results for the treatment groups were compared with controls. Hyperglycemic infants had lower birth weights than controls. Hyperglycemic infants treated with glucose reduction remained <60 kcal/kg/day longer than control or insulin infusion groups (8.6 +/- 1.3 days vs. 4.1 +/- 0.2 and 5.5 +/- 0.6 days). No infants became hypoglycemic during insulin infusion. There was no difference in baseline blood levels of IGF-I or IGF-II among the groups, and these growth factors did not change in response to hyperglycemia. Hyperglycemic infants had baseline levels of insulin which were similar to normal controls, and endogenous insulin increased in response to hyperglycemia in 15 of the 23 infants who developed hyperglycemia. IGF-I and IGF-II are not related to hyperglycemia. In our population, hyperglycemic infants did not have baseline insulin deficiency and most had a normal insulin response to hyperglycemia. Insulin infusion appears safe in these infants and helped to maintain normal caloric intake, whereas glucose reduction was associated with a prolonged caloric deprivation.
Evidence from randomized trials in hyperglycemic VLBW neonates is insufficient to determine the effects of treatment on death or major morbidities. It remains uncertain whether the hyperglycemia per se is a cause of adverse clinical outcomes or how the hyperglycemia should be treated. Much larger randomized trials in hyperglycemic VLBW neonates that are powered on clinical outcomes are needed in order to determine whether, and how, the hyperglycemia should be treated.