The metabolic syndrome as a risk factor for venous and arterial thrombosis

The metabolic syndrome is a cluster of risk factors for atherosclerosis. Although a universally accepted definition is still lacking because available classifications present slightly different diagnostic criteria, the metabolic syndrome is now recognized as a serious public health problem that affects up to 45% of the population >50 years of age in the United States and approximately 20 to 25% of the adult population in Europe. To diagnose the metabolic syndrome, the concomitant presence of at least three components, among them visceral obesity defined by the measurement of the waist circumference, elevated blood pressure, hyperglycemia, hypertriglyceridemia, or reduced high-density lipoprotein cholesterol levels, is required. The concomitant presence of these risk factors, and thus the presence of the metabolic syndrome, is associated with inflammatory and hypercoagulable states that through increased levels of coagulation factors, reduction in fibrinolysis, endothelial dysfunction, and platelet hyperreactivity may predispose patients to develop cardiovascular events. Several studies have consistently shown that patients with the metabolic syndrome are at significantly increased risk of diabetes, coronary artery disease, and ischemic stroke. A few recent studies suggest that the metabolic syndrome may also play a role in the pathogenesis of venous thromboembolism, but this latter finding needs confirmation by large clinical studies.