Research Article Arterial stiffness and orthostatic blood pressure changes in untreated and treated hypertensive subjects Athanase D. Protogerou, MD*, George S. Stergiou, MD, Panagiota Lourida, MD, and Apostolos Achimastos, MD Hypertension Center, 3rd University Department of Medicine, Sotiria Hospital, University of Athens, Athens, Greece Manuscript received December 20, 2007 and accepted March 26, 2008 Abstract Carotid-femoral pulse wave velocity (PWV), an integrated marker of segmental aortic stiffness, was recently proposed as one of the underlying mechanisms inducing orthostatic hypotension in the elderly with marked arterial rigidity. We examined the relationship between PWV (Complior; Colson, Paris, France) and orthostatic blood pressure (BP) changes, measured repeatedly, over a wide range of age and arterial stiffness. Sixty-nine hypertensive subjects (age, 37 to 76 years; 39 untreated and 30 treated) were studied. BP, in both sitting and erect position, was measured at two occasions a few weeks apart, and in between PWV was assessed by means of pulse wave analysis. In untreated hypertensive subjects, the orthostatic alterations in systolic, but not in diastolic blood pressure (DBP), were inversely related to PWV, independently from age, gender, mean BP, and diabetes mellitus. The greater the aortic stiffness the larger was the systolic blood pressure (SBP) decrease during upraises. On the contrary, no such association was found between PWV and orthostatic changes of BP in treated hypertensive subjects. These results suggest the presence of a pathophysio- logical association between arterial stiffening and BP postural changes. Antihypertensive drug treatment, as well as other factors that have not been evaluated in the present study, might have modulated this association. However, it might be argued that a causal association between arterial stiffness – disturbed baroreflex sensitivity – postural BP changes, even in subjects without pronounced vascular aging or orthostatic hypotension, is implied. J Am Soc Hypertens 2008;2(5): 372–377. © 2008 American Society of Hypertension. All rights reserved. Keywords: Aortic stiffness; pulse wave velocity; orthostatic hypotension; mean blood pressure. Introduction Large artery (aortic) stiffness may be easily and repro- ducibly assessed by simple automatic devices that measure pulse wave velocity (PWV). 1 Carotid-femoral PWV, an index of segmental aortic stiffness, is an independent pre- dictor of overall and cardiovascular mortality in hyperten- sive subjects and also in the general population. 2,3 The increase of PWV reflects not only the aging process but is also further accelerated by various cardiovascular risk fac- tors including hypertension, diabetes mellitus, smoking, and hypercholesterolemia. 4 Therefore it may be considered as an integrated marker of the arterial wall damage. It was recently suggested that aortic stiffness (carotid- femoral PWV) might be one of the underlying mecha- nisms inducing orthostatic hypotension in the elderly. 5 Arterial wall stiffness in barosensitive regions (e.g., aorta) may reduce baroreceptor sensitivity by restricting their ability to stretch and relax in response to blood pressure (BP) changes. 5–9 Data from repeated recordings of orthostatic changes of BP and their association with arterial stiffness in younger subjects are lacking. Because the association of arterial stiffness and barore- flex sensitivity has been described even in healthy sub- jects, 7 we sought to determine the relation between aortic stiffness and postural BP changes in a wide range of age and PWV. Because antihypertensive drug treatment not only lowers peripheral resistance, and thereby brachial BP, but also affects large arteries’ function and struc- ture, 10 we analyzed untreated and treated hypertensive subjects separately, in order to investigate potential dif- ferences. Conflict of interest: none. *Corresponding author: Athanase D. Protogerou, MD, Hyper- tension Center, 3 rd University Department of Medicine, 152 Me- sogeion Av., Athens 115 27, Greece. Tel: 0030 210 7763117; fax: 0030 210 7719981. E-mail: aprotog@med.uoa.gr Journal of the American Society of Hypertension 2(5) (2008) 372–377 1933-1711/08/$ – see front matter © 2008 American Society of Hypertension. All rights reserved. doi:10.1016/j.jash.2008.03.011