High-density lipoprotein (HDL) and low-density lipoprotein (LDL) (HDL and LDL)

High-density lipoprotein (HDL) and low-density lipoprotein (LDL) are complex macromolecular particles composed of apolipoproteins, phospholipids, triglycerides, and cholesterol that facilitate the transport of lipids through the bloodstream (Source: StatPearls, Lipoprotein Metabolism). LDL is primarily responsible for delivering cholesterol from the liver to peripheral tissues; however, when present in excess, it can become oxidized and trapped within the arterial wall, initiating the process of atherosclerosis (Source: NIH, LDL and HDL: Bad and Good Cholesterol). Conversely, HDL is involved in reverse cholesterol transport, a protective mechanism that removes excess cholesterol from tissues and atherosclerotic plaques, returning it to the liver for excretion (Source: PubMed, Role of HDL in Cardiovascular Disease). This entry is considered 'incorrect' as a single target because it combines two distinct physiological entities with opposing roles in cardiovascular health. Pharmacological management typically aims to lower LDL-C levels using statins, PCSK9 inhibitors, or ezetimibe to reduce the risk of major adverse cardiovascular events. While raising HDL-C was long considered a therapeutic goal, clinical trials for drugs like CETP inhibitors have demonstrated that the functional quality of HDL may be more clinically relevant than its absolute concentration (Source: Journal of the American College of Cardiology).

Other names

HDL-CLDL-CAlpha-lipoproteinBeta-lipoproteinGood cholesterolBad cholesterolLipoprotein particles

Modulation of lipoprotein levels through various pathways: HMG-CoA reductase inhibition (statins) to reduce cholesterol synthesis; PCSK9 inhibition to increase LDL receptor density; NPC1L1 inhibition (ezetimibe) to block intestinal absorption; and PPAR-alpha activation (fibrates) to enhance triglyceride clearance and HDL synthesis.