Glucose-insulin system

The glucose-insulin system has been presented in a context of classic control theory as a combination of a P1D control and predictive control. This context may be too simplified. With a network of sensors, a complex traffic of nutrients and metabolites, and day to day variations in food intake, it is difficult to assign a single controlled variable, like plasma glucose concentration, to the control system. Equally important variables could be intracellular glucose concentration, the flux of fatty acids and amino acids. 

Cunningham JJ (1998a) The glucose/insulin system and vitamin C implications in insulin-dependent diabetes mellitus. Joumai of the American Coiiege of Nutrition 17, 105-8. 

Amin R, Ross K, Acerini CL, Edge JA, Warner J, Dunger DB. Hypoglycemia prevalence in prepubertal children with type 1 diabetes on standard insulin regimen use of continuous glucose monitoring system. Diabetes Care 2003 26(3) 662-7. 

I. M. Tolic, E. Mosekilde, and ). Sturis Modeling the insulin-glucose feedback system the significance of pulsatile... 

The present chapter has several aims. The first is to describe the glucose-insulin control system in a fashion that includes the most important physiological and biochemical processes governing the glucose metabolism. The second is to demonstrate how biosimulation models can be built and to show the quantitative arguments behind the setup of model equations. The third is to use these biosimulation models to reveal critical mechanisms in the glucose handling and to relate these mechanisms to experimental and clinical problems. 

As previously mentioned, the glucose-insulin control system is often regarded as a simple system to keep the plasma glucose concentration within narrow limits. In this context it has been compared to technical control systems and described by simple, often linear or linearized models. Section 6.2 of this chapter gives an outline of classic control and underlines some of the peculiarities of biological control systems. 

The analysis reveals that the glucose-insulin control system functions as a regulator of the flux of nutrients - not only glucose - between the different organs in a smooth, controlled manner. In this control, the nervous system has an important... 

The features of the hepato-portal system together with the previous mentioned integral control supports the concept that the glucose-insulin control system is not so much a control of plasma glucose concentration as a system that controls the nutrient fluxes after a meal. 

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