Figure 2.

Schematic representation of the link between chronic diseases, malnutrition, hypercatabolic syndrome, and autophagy. The increase in catabolism induced by chronic diseases and malnutrition favors the activation of autophagy to guarantee the cells sufficient energy and materials to cope with accelerated metabolism. This results in a cascade of events, leading to protein disarrangements (the severe alteration of the protein components of the body), and then to metabolic impairment. This creates a vicious circle which, in the absence of adequate nutritional interventions, maintains and favors the hypercatabolic syndrome. Furthermore, in patients with advanced chronic diseases, like the end stage of CHF, autophagy is severely triggered, and the autophagic machinery may also drive the cells to self-destruction.