Lipoprotein metabolism in liver disease.

In this review we have endeavored to emphasize the central role of the liver in normal lipoprotein metabolism and to demonstrate how derangements in these metabolic processes can lead to abnormalities characteristic of liver disease. Since changes in the concentration and composition of plasma lipids and lipoproteins occur frequently in liver disease, these findings may be useful in following the clinical course of patients with liver disease of various causes. It should be emphasized that elevated plasma triglycerides and cholesterol are due to underlying defects in lipoprotein metabolism and should not be confused with primary hyperlipidemia. Impaired cholesterol esterification, abnormal lipoprotein electrophoretic patterns and lipoprotein compositional changes, all reflect abnormalities of lipoprotein metabolism that are secondary to hepatocellular injury or cholestasis. These abnormalities are very sensitive indicators of fundamental metabolic defects that are related in part to LCAT and apoprotein activator deficiencies, impaired H-TGL and LPL activity and, perhaps, defective remnant lipoprotein clearance by the liver. Since these abnormalities tend to improve with clinical recovery they have proved to be reliable and sensitive indicators of hepatic function and thus, are useful in the assessment of liver disease.