[Hypertrophy of the arterial wall and arterial rigidity]

The purpose of this article is to review the relations between hypertension-induced hypertrophy and stiffness of the arterial wall. Arterial remodeling was assessed based on the geometrical (lumen and arterial wall thickness) and functional (distensibility and Young's elastic modulus) properties of large and medium-sized arteries in hypertensive and normotensive subjects. Several clinical and animal studies have shown that arterial wall hypertrophy, which normalizes circumferential wall stress, does not increase the elastic modulus of arterial wall material during chronic essential hypertension. The structural changes associated with hypertension and those associated with aging have opposite effects on arterial distensibility at a given transmural pressure (isobaric distensibility): arterial distensibility increases with hypertension and decreases with aging. Thus, hypertension cannot be considered equivalent to aging. The structural and functional changes in arterial wall material associated with hypertension-induced hypertrophy may explain why medium-sized arteries maintain their distensibility characteristics despite a distending pressure increase; these changes may not be associated with an intrinsic (isobaric) decrease in the distensibility of large arteries.