Systolic hypertension in the elderly: arterial wall mechanical properties and the renin–angiotensin–aldosterone system

BACKGROUND: Systolic hypertension in the elderly involves an increase of arterial stiffness and early wave reflections, both of them causing a predominant or selective increase of systolic blood pressure. The mechanisms for such alterations remain largely unknown. DESCRIPTION AND RESULTS: The development of systolic hypertension includes constantly an age-related increase of sodium sensitivity and of endothelial dysfunction, both responsible for phenotypic changes of aortic smooth muscle cells with collagen accumulation and increased stiffness. 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. Gene polymorphisms related to the renin-angiotensin system may participate in this evolution. CONCLUSION: This process contributes to accelerating the increase in pulse pressure and arterial stiffness with age, and therefore to the development of cardiovascular risk.