Objective: Twenty-four-hour blood pressure variability (BPV) predicts cardiovascular complications in hypertension, but its association with pulse wave indices (central arterial systolic pressure or CASP, pulse wave velocity or PWV, and augmentation index or AIx) is poorly understood. In the present study we assessed the degree of the impact of 24-hour BPV on 24-hour pulse wave indices.

Methods: Brachial BP was measured non-invasively over the 24-hours by an electronic, oscillometric, automated device (BPLab) in 661 uncomplicated, treated or untreated, hypertensive patients. Digitalized oscillometric waveforms were analyzed by a validated algorithm in order to obtain pulse wave indices. Twenty-four-hour BPV was calculated as unweighted (SDu) or weighted standard deviation (SDw) of the mean blood pressure, or as average real variability (ARV). Patients were classified in two groups according to whether the 24-hour BPV was below or above the median of the whole group.

Results: Twenty-four-hour systolic blood pressure variability (SBPV) showed a direct and significant relation with CASP (r=0.28 SDu, r=0.40 SDw, r=0.34 ARV), aortic PWV (r=0.10 SDu, r=0.21 SDw, r=0.19 ARV) and AIx (r=0.17 SDu, r=0.27 SDw, r=0.23 ARV). After adjustment for age, gender, body mass index, antihypertensive treatment and 24-hour SBP, the relationship was attenuated, but was still significant for all measures, X for AIx. Pulse wave indices were larger in patients with high than in those with low BPV: after adjustment these differences were abolished for AIx. Diastolic BPV showed a weak association with pulse wave indices.

Conclusions: In hypertensive patients 24-hour SBPV is moderately and independently associated with 24-hour CASP, wave reflection and stiffness.