The insulin resistance syndrome: impact on lipoprotein metabolism and atherothrombosis

Abstract

Insulin resistance is a common metabolic abnormality that is associated with an increased risk of both atherosclerosis and type 2 diabetes. The phenotype of insulin resistance includes a dyslipidemia characterized by an elevation of very low-density lipoprotein triglyceride, a reduction in high-density lipoprotein cholesterol, and the presence of small, triglyceride-enriched low-density lipoproteins. The underlying metabolic abnormality driving this dylipidemia is an increased assembly and secretion of very low-density lipoprotein particles, leading to an increased plasma level of triglyceride. Hypertriglyceridemia, in turn, results in a reduction in the high-density lipoprotein level and the generation of small, dense low-density lipoproteins; these events are mediated by cholesteryl ester transfer protein. In addition, hypertension, obesity, and a prothrombotic state are also integral components of the insulin resistance syndrome. In this review, we will provide a pathophysiologic basis, based on studies on humans and in tissue culture, for the dyslipidemia of insulin resistance. We will also review the effects of insulin resistance on the coagulation and fibrinolytic pathways. It is hoped that this review will allow health professionals better to evaluate and treat their patients with insulin resistance, thereby reducing the very much increased risk of atherosclerotic cardiovascular disease carried by these individuals.