Background: The prognostic significance of the variability in systolic blood pressure (sBP) for cardiovascular events has been highlighted recently. Although increased arterial stiffness has been proposed as a potential mechanism, the relationship between sBP variability and arterial stiffness has not been examined directly. Therefore, the aim of the current study was to determine whether increased arterial stiffness is associated with increased blood pressure variability based on 24hour ambulatory blood pressure monitoring (ABPM) in a subset of older individuals from the Anglo-Cardiff Collaborative Trial.

Methods: Aortic stiffness was assessed by measuring the carotid-femoral pulse wave velocity (aPWV) in individuals aged over 50 years. Subjects also underwent 24 hour ABPM.

Results: Data concerning 24 hour ABPM and arterial stiffness were available in 204 individuals with an average age of 67±6years. When individuals were grouped according to tertiles of aPWV there was a significant increase in the variability of day sBP from the lowest to highest tertile (12.52±3.72 v 14.23±3.99, P<0.001). However, this relationship was not apparent for night sBP (11.86±4.49 v 12.16±4.61, P=0.4). In stepwise linear regression analyses, aPWV was independently associated with day sBP variability after adjustment for age, gender, mean day sBP and medication. However, only mean night sBP was associated with night time sBP variability.

Conclusion: These data support the hypothesis that individuals with increased sBP variability have elevated arterial stiffness. These data require confirmation in a large population, with outcome data.