Hypertension is a disease of the blood vessel wall, not of the blood pressure, as is traditionally thought. As such, the concept of hypertension needs to be redirected to address atherosclerosis, the cause of most cardiovascular events. The presence of an atherosclerotic plaque is a late manifestation of a disease process that probably begins in the endothelium that lines the blood vessel wall. The blood vessel is a series of sequential vascular components that differ in structure and function and have different determinants of compliance. The large conduit arteries have a capacitor function and contain elastin and collagen; elasticity of these arteries is pressure dependent. Elasticity of the smaller reflecting sites into which these conduits branch and taper, is more dependent on nitric oxide from the endothelium and contributes to oscillations in the pulse wave; it is minimally pressure dependent. Elasticity of the arterioles, which are the resistance vessels and contain very little collagen, is probably not pressure dependent. There are striking differences, therefore, between compliance of the conduit arteries and reflecting sites and resistance in the arterioles. A number of studies have looked at the effects of aging, hypertension, diabetes, smoking, and atherosclerosis on endothelial dysfunction, capacitive compliance. All of the studies reviewed in this presentation demonstrated decreased small artery elasticity or compliance and increased endothelial dysfunction with each of the disease processes. Just as decreased arterial compliance may be the clinical marker for endothelial dysfunction, the marker for cardiovascular risk is endothelial dysfunction, not blood pressure itself.
|Original language||English (US)|
|Journal||American Journal of Managed Care|
|Issue number||12 SUPPL.|
|State||Published - Aug 1 1999|