Therapy of hyperlipoproteinemia

Triglycerides and cholesteryl esters are non-polar molecules and, therefore, insoluble in aqueous fluids such as blood. Lipid transport in blood is only possible the formation of lipoproteins. This article proposes a concept for the treatment of hyperlipidemias that is based on lipoprotein pathology. The liver secretes the triglycerides and cholesteryl esters in the form of very-low-density lipoproteins (VLDL). Lipolysis hydrolyzes VLDL triglycerides, providing tissues with fatty acids. and gives rise to relatively cholesterol-enriched intermediate-density lipo- proteins (IDL) and low-density lipoproteins (LDL). IDL and LDL are removed from plasma by receptor-mediated cellular uptake. An increased plasma concentration of VLDL ensues in predominant hypertriglyceridemia (e.g. triglycerides 9 mmol/l, cholesterol 7 mmol/l). VLDL are not considered to be directly atherogenic, but increased levels of VLDL often occur together with an atherogenic decrease of high-density lipoproteins (HDL). Elevated VLDL levels respond well to dietary measures; fibric acid derivatives, nicotinic acid and omega-3-fatty acids also effectively lower VLDL. An increase in IDL leads to both hypertriglyceridemia (e.g. 3 mmol/l) and hypercholesterolemia (e.g. 7 mmol/l). IDL are considered directly atherogenic. Hyperlipidemias due to IDL respond to the same interventions as those due to VLDL. An increased blood level of LDL leads to hypercholesterolemia (e.g. 7 mmol/l) with normal triglyceride levels (e.g. 1 mmol/l); LDL are considered directly atherogenic. Dietary measures can reduce LDL levels by about 10%, but pharmacological treatment by inhibitors of cholesterol synthesis ('statins') and by ion exchange resins is much more effective.(ABSTRACT TRUNCATED AT 250 WORDS)