Energy expenditure and substrate metabolism in liver cirrhosis.

Increased energy needs, a reduced synthesis of endogenous substrates and a limited energy yield from exogenous substrates characterize the metabolic dilemma in patients with liver cirrhosis. The metabolic features observed in cirrhosis are highly variable and cannot be considered as clear-cut phenomena. They obviously differ in certain aspects from the metabolic situations known from starvation or type 2 diabetes mellitus. This is not contrary to the idea that cirrhosis may resemble certain aspects of these 'standard' situations. Cirrhosis-induced disturbances in fuel homeostasis cannot be predicted from clinical and biochemical parameters of the disease. Most of the metabolic picture is present at a very early stage of liver disease. Many metabolic features are independent of the clinical course of liver disease, suggesting that they are an early and extra-hepatic manifestation. A better understanding of the variance of cirrhosis-induced alterations in metabolism may come from characterization of the metabolic 'genotype' which adds to disease-related factors in the individual patient.