Endothelial dysfunction: methods of assessment & implications for cardiovascular diseases.

The endothelium is a thin monocellular layer lining the entire human vascular system, separating blood from interstitium. It plays a core role in the vascular tone by releasing a variety of vasoactive substances, such as nitric oxide (NO) and endothelin. In addition to regulating vasomotion, the healthy endothelium also has anti-thrombotic (through prostacyclins), anti-inflammatory (through developmental endothelial locus-1{Del-1}) and anti-proliferative (through NO and prostaglandin I2) properties. All such mechanisms are regulated by a strict balance amongst several agonist and antagonist biochemical substances secreted by the endothelium. Endothelial dysfunction (ED) is a systemic process in which the endothelium loses the ability/capacity to maintain vascular equilibrium. ED is strongly associated with cardiovascular risk factors/diseases and can be assessed by a number of invasive and non invasive methods. Strict physiological and/or pharmacological management of cardiovascular risk factors improves the functional status of the endothelium and reduces the risk of future cardiac events. This review will provide an overview of the modern perception of endothelial biology, the methods of its assessment and interaction of the endothelium with cardiovascular risk factors and prognosis.