Feedback Control of Blood Glucose

Abstract

Our interest in the control of blood glucose was stimulated by the finding of oscillations in both blood glucose and insulin after oral glucose administration.A study was made of the phase and magnitude relations that exist in these oscillations with a view to delineating behaviour of the blood glucose - insulin feedback loop operative after oral glucose administration. Implicit in this was the need to explain why this feedback loop behaves differently with oral and intravenous glucose loads. Recent work suggests that this is due in part to insulin secretion mediated by the gastrointestinal hormones, in particular gastrin and secretin.Presented here are experimental studies of the oscillatory transient response to oral glucose in man, studies designed to identify functional involvement of the gastrointestinal hormones in shaping this response, and, finally, computer simulation studies which illustrate some of the determinants of system dynamic response to oral glucose.