title: Systolic hypertension in the elderly: arterial wall mechanical properties and the renin-angiotensin-aldosterone system.
abstract: 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.
  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.
  
  
  CONCLUSIONS
  This process contributes to accelerating the increase in pulse pressure and arterial stiffness with age, and therefore to the development of cardiovascular risk.
authors.affiliation: Diagnosis Center, Hôtel-Dieu Hospital, Paris, France. michel.safal@htd.ap-hop-paris.fr
authors.forename: Michel E
authors.initials: ME
authors.lastname: Safar
mesh_terms: D000368:Aged; D001158:Arteries / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology*; D006801:Humans; D006977:Hypertension, Renal / Q000503:physiopathology*; D012084:Renin-Angiotensin System / Q000502:physiology*; D013314:Stress, Mechanical