Medical semiology of mechanical factors and vascular aging in the elderly

Abstract

Systolic hypertension in the elderly involves increased arterial stiffness and disturbed wave reflections, both of them causing a predominant or selective increase of systolic blood pressure. The development of systolic hypertension includes constantly an age-related increase of sodium sensitivity and endothelial dysfunction, both responsible for phenotypic changes of aortic smooth muscle cells, with collagen accumulation and increased stiffness of wall material. In the presence of a high sodium diet and under the influence of angiotensin II and aldosterone, a higher number of attachments between vascular smooth muscle cells and collagen fibers develop, causing a supplementary increase in stiffness independent of the mean blood pressure, together with the occurrence of early wave reflections. This process contributes to accelerate the increase in pulse pressure and arterial stiffness with age, and thus to favor the development of cardiovascular risk.