High-density lipoproteins: Metabolism and protective roles

Abstract High-density lipoproteins (HDLs) are lipid–protein complexes that mediate the transport of cholesterol from non-hepatic tissues to the liver for excretion from the body, a process known as reverse cholesterol transport. Several other protective functions of HDLs have been identified, along with modifications to HDL proteins and lipids that cause them to lose their protective function in ways not reflected by the level of HDL-cholesterol in plasma. This chapter outlines the biochemical pathways of HDL formation and metabolism, gene mutations affecting HDL-cholesterol level, potential protective actions of HDLs and modifications that cause these actions to be lost.