Modeling and identification of endocrine-metabolic systems. Theoretical aspects and their importance in practice

Some guidelines for modeling, identification, and validation in endocrinology and metabolism are presented. Fundamentals based on recent theoretical developments are given, and their essential role for solving physiological and clinical problems is shown. Concepts and issues discussed include a priori and a posteriori identifiability; optimal experiment design; assessment of model validity; simple and complex models; compartmental and noncompartmental models. Recent studies on the glucose-insulin system and on ketone body metabolism are used to illustrate the methodological line of thought discussed in the paper.