Third Annual World Congress on the Insulin Resistance Syndrome

Abstract

This is the second of three articles reviewing presentations at the 3rd Annual World Congress on the Insulin Resistance Syndrome, San Francisco, California, 17–19 November 2005. At a symposium cosponsored by the International Society of Diabetes and Vascular Disease (www.dvdres.com), Peter Grant (Leeds, U.K.) discussed the role of insulin signaling pathways in acute coronary syndrome (ACS), pointing out that type 2 diabetes is characterized by fasting hyperglycemia, usually with obesity, accompanied by a clustering of CVD risk factors, with 80% of persons with type 2 diabetes dying of premature vascular disease. In persons with diabetes, glycemic abnormality is superimposed on the abnormalities of the insulin resistance sydrome, so that similar considerations apply to the larger group of persons with insulin resistance. Indeed, we may underestimate the importance of glycemic abnormality in cardiovascular disease (CVD), with recent studies suggesting that some 40% of persons with myocardial infarction have diabetes, with an additional 40% having impaired glucose tolerance (1). The cardiovascular manifestations of insulin resistance sydrome constitute a series of inflammatory atherothrombotic processes, with atherectomy specimen analysis showing more thrombus, more macrophage infiltration, and a greater area of lipid-rich atheroma in persons with diabetes (2). Furthermore, type 2 diabetes alters fibrin structure, coagulation, and platelets in a prothrombotic direction (3). It is not apparent why insulin resistance should be linked to atherosclerosis. The thrifty genotype hypothesis suggests that there is a survival advantage to insulin resistance during periods of feast alternating with famine (4), but that chronic exposure to high nutrient intake converts the organism to the phenotype of insulin resistance sydrome and diabetes, with energy preferentially stored in the liver and in fat and with the clustering of risk markers we have come to identify with insulin resistance. The common-soil hypothesis suggests that diabetes and CVD are the same condition, …