We aim to investigate whether 24-hour (24-h) aortic blood pressure variability (BPV) is better associated with carotid intima-media thickness (CIMT) and cross-sectional area (CCSA)than 24-h brachial BPV.Design and Method:
445 consecutive individuals (aged 54.0 ± 13.0 years, 57.1% men) referred for consultation on hypertension underwent brachial and aortic 24-h ambulatory blood pressure monitor with a validated device (Mobil-O-Graph NG apparatus, Germany). The average real variability (ARV) and time-weighted standard deviation (wSD) of 24-h systolic BP were calculated. The internal and external lumen diameters and IMT of bilateral common carotid arteries were measured by ultrasonography. CCSA was calculated by carotid lumen diameters. Averages of bilateral CIMT and CCSA were used for the analysis.Results:
In the univariate analysis, brachial and aortic BPVs all significantly correlated with CIMT and CCSA (P < 0.001, Table 3). In the multiple regression analysis after adjustment for confounders, AVRs and wSDs in both brachial and aortic were associated with CIMT, but no difference was found between brachial and aortic BPVs. CCSA was only significantly associated with aortic wSD. In the multiple logistic regression analysis as shown in Figure 2, CIMT > 900 μm was significantly and independently associated with aortic ARV and wSD (OR = 1.33; 95% CI: 1.02–1.74; OR = 1.58; 95% CI: 1.16–2.15; respectively), but not with brachial ARV or wSD. CCSA > 90th percentile was significantly and independently associated with aortic ARV (OR = 1.41; 95% CI: 1.02–1.96), rather than brachial ARV. No association was found between CCSA > 90th percentile and wSDs. In ROC curve analysis, aortic wSD identified CIMT > 900 μm and CCSA > 90th percentile better than brachial wSD (AUC: 0.72 VS. 0.69, P = 0.046; 0.72 VS. 0.68, P = 0.01; respectively), no difference was found between aortic and brachial ARVs.Conclusions:
Although brachial and aortic 24-h systolic BPVs were both significantly associated with CIMT and CCSA, the 24-h aortic systolic BPV was superior to brachial systolic BPV in the identification of arterial damage.