P106: Aortic Stiffness and Central Systolic Pressure Are associated with Orthostatic Hypotension in Patients with Chronic Kidney Disease

Objective Orthostatic hypotension (OH) is common cardiovascular problem affecting older adults, and is associated with falls, stroke and chronic kidney disease (CKD). This postural drop (PD) in blood pressure (BP) has been independently associated with increased aortic stiffness in older adults. Aortic stiffness is a modifiable cardiovascular risk factor, and measureable non-invasively. We investigated the association between OH, aortic stiffness and central aortic systolic pressure (CSP) in CKD patients (ACADEMIC cohort). Design and method Postural BP changes were measured in one-hundred and forty-six patients (mean age 68.6 SD ± 11.4, 75% male, 21% diabetic) using 24-hour-ambulatory blood pressure monitoring with postural sensing (Diasys Integra II®, Novacor, France). Patients were divided into those with systolic postural drop (SPD, n = 23, mean standing systolic BP < mean lying systolic BP) versus those without (n = 123). Complior® (Artech Medical, France) measured aortic stiffness as carotid-femoral pulse wave velocity (cf-PWV) and peripheral arterial stiffness as carotid-radial PWV (cr-PWV). Sphygmocor® (Atcor, Australia) measured CSP and augmentation index (AI) from the radial artery. Results Cf-PWV and CSP were significantly higher in CKD patients with SPD versus those without (15.2m/s vs 12.7m/s, p < 0.001, 148 mmHg vs 136 mmHg, p = 0.012). Multivariate logistic regression showed SBP remained significantly associated with aortic stiffness (p = 0.002, OR = 1.45 95%CI = 1.15–1.77) and CSP (p = 0.026, OR = 1.031, 95%CI = 1.00–1.06), independent of age, eGFR, diabetes, smoking pack-years, cholesterol, height and weight. RAI (32.1% vs28.9%, p = 0.093) and cr-PWV (11.0m/s vs 11.2m/s, p = 0.62) were not significantly different between groups. Conclusion Increased aortic stiffness and CSP are independently associated with OH. Stiff central arteries, rather than peripheral, contribute more to OH.