Insulin kinetics, models, and delivery schedules.
Several insulin models are examined as to their responses to various insulin inputs and glucose utilization and production control. It is shown that the action of insulin on glucose utilization correlates best with model compartments having a 30--50-min delay compared with plasma, whereas glucose production control is rapid. It is further shown that whereas the predicted plasma insulin response curves are nearly the same for various models, the responses at possible sites of action (e.g., receptors or slowly exchanging tissues) can differ considerably for the different models. By determining the parameter values for the glucose-insulin system in a patient through isotope kinetics studies, it is possible to use the patient's model either as a direct algorithm for insulin delivery or as a tool for studying glucose control under various conditions and thus aid in the design of appropriate algorithms or schedules for insulin delivery.