Background: It is well documented that arterial stiffness is age-related. The purpose of the present study was to evaluate to what extent age affects arterial stiffness in patients with essential or white coat hypertension (WCH) and the effect of previous antihypertensive medication.

Methods: We studied 850 patients, untreated or after a 15 days wash-out period, in our outpatient clinic. All patients underwent 24h ambulatory blood pressure monitoring (ABPM) and full biochemical assay. Large-artery stiffness and arterial wave reflections were evaluated by measuring carotid-femoral pulse wave velocity (PWVc-f) and augmentation index (AIx) respectively.

Results: Patients were classified in four groups, according to the ABPM results. 294 never treated patients with essential hypertension (group 1), 322 patients with essential hypertension after the wash-out period (group 2), 112 never-treated patients with WCH (group 3) and 322 patients with WCH after the wash-out period (group 4). Univariate analysis showed a significant correlation of age with PWVc-f in groups 1, 2 and 3 (r = 0.43, 0.46 and 0.38 respectively, p < 0.001) but not in group 4 (r = 0.17, p = NS). Furthermore, age was positively correlated with AIx in all groups (r = 0.53, 0.38, 0.47 and 0.67 respectively, p < 0.0001). Finally, significant correlation of age with systolic blood pressure was found in groups 1 and 4 (r = 0.20 and 0.30 respectively, p < 0.001) and with diastolic blood pressure in group 2 (r = 0.37, p < 0.0001).

Conclusion: Age affects arterial stiffness differentiating in PWV or AIx. In patients with essential hypertension as well as in patients with WCH, the age effect is of similar magnitude whereas the effect of previous medication use is minimal.