[Some physiopathologic features of metabolic syndrome]

Metabolic syndrome (MS) is a common condition strongly associated with the development of type 2 diabetes and coronary heart disease (CHD). High triglycerides (TG) and low high density lipoprotein cholesterol (HDL-C) often occur together and represent the fundamental dyslipidemia of patients with MS. This abnormal lipoprotein profile is a major risk factor for premature cardiovascular disease. This review briefly discusses new findings on structure and functions of HDL in the atherogenic dyslipidemic condition known as MS. While the knowledge of the association between HDL-C and CHD began with the observation of an inverse relationship between HDL-C values and CHD risk, information in recent years shows the important role of HDL function in the pathogenesis of atherosclerosis. HDL particles are heterogeneous in structure, intravascular metabolism and antiatherogenic activity. Reductions in HDL-C concentrations, as seen in MS, are frequently associated with an abnormal HDL subclass distribution, altered HDL chemical composition, reduced antiinflamatory and antioxidative properties, and low capacity to promote cholesterol efflux. Deficiency of HDL particle number and attenuated antiaterogenic activity favor accelerated atherosclerosis. These data justify renewed emphasis on low HDL-C as a major risk factor in the prevention and treatment of CHD. Pharmacological interventions that increase HDL-C can also improve the quality and biological activities of HDL particles. Fibrates, nicotinic acid, cholesteryl ester transfer protein inhibitors, and reconstituted HDL are being investigated. Patients with MS constitute a high risk group that would particularly benefit from intervention to rise HDL-C.