Serum Insulin Response to Slow-rise Glucose Infusion in “Genetic Prediabetics” (Offspring of Two Diabetic Parents)

The insulin response to a programed slow-rise glucose infusion designed to mimic the postprandial rise in glucose was studied in five offspring of two diabetic parents (ODP) and seven normal subjects. The ODP had higher mean blood glucose levels towards the end of the infusion and during the postinfusion period. The rates of glucose disappearance calculated during the postinfusion period were comparable in the two groups. Despite the apparent similarity of serum insulin levels of ODP and normal subjects, the amount of insulin secreted per unit of glycemie stimulus was lower in the ODP group. When the glucose infusion test was preceded by an acute load of glucose, similar findings in the insulin secretory dynamics were found in the ODP group. These data suggest that an impairment in insulin secretion exists in ODP when they are challenged by the slow rise of blood glucose achieved by this type of an intravenous glucose infusion.