Objective: Arterial stiffness may be involved in the impairment of the arterial baroreflex. In the present study the associations between arterial stiffness and cardiovagal baroreflex sensitivity (BRS) and between BRS and postural blood pressure (BP) changes were investigated within the framework of the Rotterdam Study.
Methods: Arterial stiffness was determined by aortic pulse wave velocity and the carotid distensibility coefficient. Continuous recording of the R-R interval and finger BP was performed with the subject resting supine, and BRS was estimated from the spontaneous changes in systolic BP and corresponding interbeat intervals. Measures of aortic stiffness or carotid distensibility and BRS were available in 2490 and 2083 subjects, respectively. The association between arterial stiffness and ln BRS was investigated by multivariate linear regression analysis and then by analysis of covariance, comparing BRS by quartiles of arterial stiffness.
Results: The mean age of the subjects was 71.7 +/- 6.6 (41.7% men). Aortic stiffness was negatively associated [beta = -0.029; 95% confidence interval (CI): -0.040, -0.019] and the carotid distensibility coefficient positively associated with BRS (beta = 0.017; 95% CI: 0.010, 0.024). An orthostatic decrease in systolic BP was absent in 1609 subjects, between 1 and 10 mmHg in 502 and >10 mmHg in 269 subjects, with corresponding mean values (95% CI) of ln BRS of 1.47 (1.44-1.51), 1.43 (1.37-1.49) and 1.36 (1.28-1.44) ms/mmHg (test for trend P < 0.019). An orthostatic decrease in diastolic BP was absent in 1123 subjects, 1-10 mmHg in 1057 and >10 mmHg in 209 subjects, with corresponding mean values of ln BRS of 1.49 (1.45-1.53), 1.41 (1.37-1.45) and 1.45 (1.36-1.54) ms/mmHg (P < 0.04).
Conclusion: In a large population of older subjects, arterial stiffness appears to be an independent determinant of impaired BRS. Within the same population, impaired BRS was associated with orthostatic BP changes.