Causation, prevention and reversal of vascular endothelial dysfunction.

ABSTRACT

Insulin Resistance along with endothelial dysfunction give rise to a constellation of syndromes designated as IRS/MBS metabolic syndrome. Endothelial dysfunction starts early in life much before the development of structural atherosclerosis. Recent insights into vascular biology enable us to understand the molecular mechanisms underlying endothelial dysfunction, and the scope and need for prevention of "pre-clinical" coronary atherosclerosis through lifestyle modification; diet, exercise and stress management. Diminished production of nitric oxide (NO) and/or increased inactivation of NO through oxidative stress (reactive oxygen species ROS and reactive nitrogen species (RNS) are the basis of endothelial dysfunction hence increasing the bioavailability of NO and decreasing its inactivation is the aim of prevention and reversal of endothelial dysfunction. Insulin regulates constitutive NOS gene expression in endothelial cells in vivo; vasodilation is an important component of Insulin-stimulated whole body glucose uptake. Successful strategies are PPAR alpha and gamma agonists which increase NO production in endothelium; anti-oxidants such as vit. E and C; supplementation with L-arginine, tetrahydrobiopterin-BH4 or sepiapterin (precursor of BH4), SOD mimetic tempol, statins which apart from lowering cholesterol improve NO production, selective beta1 adrenoreceptor antagonists such as nebivolol; suppression of angiotensin-mediated endothelin production by ACE inhibitors and ATR blockers; CB1 receptor blockers, PKCb inhibitors, nitric oxide donors (glyceryl trinitrate and isosorbide dinitrate), dietary supplements of EPA/DHA and regular physical exercise and control of mental stress.