Correlation between the nature and amount of carbohydrate in meal intake and insulin delivery by the artificial pancreas in 24 insulin-dependent diabetics

Abstract

We have studied the effects of mixed meals and dextrose intake on blood glucose and insulin delivery by the artificial pancreas in 24 insulin-dependent diabetics. A group of 12 patients had 3 mixed meals containing at random 20, 40, and 60 g of complex carbohydrate along with protein and fat; another group of 12 diabetics, comparable in weight, age, and duration of diabetes, received at random 20, 40, and 60 g of dextrose. Dextrose ingestion led to a higher initial blood glucose increase than did the mixed meal, but the duration of blood glucose increase lasted significantly longer after the mixed meal than after the dextrose load. The areas under the curves of hyperglycemia were not significantly different. There was a high (but not linear) correlation between the total amount of insulin delivered in order to restore initial blood glucose values and the amount of CHO consumed. There was no correlation with age, body weight, duration of diabetes, nor with the nature and order of administration of the CHO load; 5.1 +/- 1.6 to 13.7 +/- 2.1 units of insulin were needed for a period of 94 +/- 11 to 132 +/- 11 min. It is suggested that some of the data obtained in this study might be useful in the programming of an open-loop insulin infusion system.