Central Artery Stiffness in Hypertension and Aging: A Problem With Cause and Consequence

Abstract

Systemic hypertension is a risk factor for many diseases affecting the heart, brain, and kidneys. It has long been thought that hypertension leads to a thickening and stiffening of central arteries (i.e., stiffness is a consequence) while more recent evidence suggests that stiffening precedes hypertension (i.e., stiffness is a cause). We submit, however, that consideration of the wall biomechanics and hemodynamics reveals an insidious positive feedback loop that may render it irrelevant whether hypertension causes or is caused by central arterial stiffening. A progressive worsening can ensue in either case, thus any onset of stiffening merits early intervention.

Keywords: arteries; blood pressure; hypertension; pulse wave analysis; vascular stiffness.

Figure 1

Possible positive feedback loop in central arteries that links local wall mechanics and global hemodynamics and renders it is irrelevant whether the initiator is (i) an increase in blood pressure that increases the structural stiffness of the wall or (ii) an increase in the structural stiffness of the wall that increases pulse wave velocity and thereby augments central pulse pressure. Clearly, the local mechanics that affects cell mechanobiology and the global hemodynamics that controls systemic physiology are linked strongly, but they need not work together to promote overall health. A similar positive feedback loop likely exists in resistance vessels and between small-and-large vessels.