PULSE WAVE VELOCITY AND CIRCADIAN VARIABILITY IN WELL CONTROLLED HYPERTENSIVE PATIENTS

Abstract

Objective: Pulse wave velocity (PWV) is the gold standard for measuring large artery stiffness. A PWV >10m/s is considered a conservative estimate of significant alterations of aortic function in middle-aged hypertensive patients. Although commonly used, there are only a few reports investigating the 24-hour variability in PWV measurements, the determination of which is important when using PWV as a clinical marker of target organ damage. The aim of this study was to investigate the variability in PWV measurements and factors that may influence PWV variability during 24 hours. Design and method: A prospective study was conducted in 55 well controlled hypertensive patients (mean age 65.8 ± 11.8 years) and 21 healthy control subjects (mean age 55.6 ± 18.9 years). In all subjects, complete blood chemistry (including SUA determination), echocardiographic examination, office and 24 h ambulatory blood pressure (BP) as well as 24 h ambulatory PWV and central (BP) measurement were performed Results: 24 hours systolic BP, central BP and PWV (p < 0.001) were significantly higher in hypertensive patients in confront to health subjects, but not diastolic BP (p = 0.140) levels. Specifically, the mean of PWV, SBP and cBP during 24 h was 9.7 (±0.3) vs 7.7 (± 0.3); 131.6 (±4.6) vs 122.8 (±5.9) and 137.7 (±4.3) vs 125.6 (± 4.2) for hypertensives and controls respectively. However, the mean of DBP during 24 h was 78.7 (±4.1) for patients and 79.4 (±5.6) for controls. Moreover, PWV of patients was significantly correlated with SBP, DBP (r = 0.411) and cBP (r = 0.717) levels (p < 0.001). Significant correlations were found between PWV of controls and SBP (r = 0.616), DBP (r = 0.499) and cBP (r = 0.579) levels (p < 0.001). PWV levels presented a small variability during the whole 24 hours (±0,3) suggesting that measurement and reproducibility of this marker are not influenced by a circadian rhythm. Conclusions: PWV assessment may be performed any time during 24 hours in an outpatient clinic. In our study, we didn’t find a circadian variability that may influence the reproducibility of PWV.