[Insulin sensitiviy and lipids]

Abstract

Insulin plays a central role in regulation of lipid metabolism, with different sites of action. In the adipose tissue, insulin inhibits lipolysis via an inhibition of the lipase, leading to reduce the flux of free fatty acids into the circulation. Insulin inhibits the VLDL production by the liver. Insulin is a potent activator of the lipoprotein lipase, promoting the catabolism of triglyceride-rich lipoproteins (Chylomicrons, VLDL). insulin promotes the clearance of LDL. Indeed, insulin stimulates apoB/E receptor (LDL-receptor) activity and enhances LDL degradation via the LDL-receptor pathway. Insulin also plays an important role in HDL metabolism since it activates LCAT activity, it reduces PLTP activity and modulates the hepatic triglyceride lipase activity. Because of the key role of insulin in lipid metabolism, we can easily understand that all diseases with impaired insulin action, such as insulin resistance or diabetes mellitus, will be characterized by important lipid abnormalities, which are important factors responsible for the increased cardiovascular risk in the patients.