Effect of circadian rhythm of blood pressure on arterial wall stiffness and on left ventricular diastolic dysfunction

Abstract

Background Arterial stiffness is a risk factor for cardiovascular morbidity and mortality. Variability of blood pressure has been reported to be related to worse cardiovascular outcome. The relationship between the arterial stiffness and the circadian rhythm of blood pressure (BP) has been controversial. The objective was to the examine impacts of BP variability on left ventricular diastolic function and arterial stiffness in the hypertensive patients. Methods Ambulatory BP monitoring, pulse wave velocity, and echocardiography were performed in 268 patients (153 males, 47 ± 11 years) with HTN and pre-HTN. BP was measured at the outpatient clinic and 24-h ABPM was performed. Using carotid femoral applanation tonometry, PWA was performed for evaluation of systemic arterial stiffness expressed as augmentation index. Echocardiograms were performed and an average of 3–6 cardiac cycles was done for all measurements including the left ventricular mass index (LVMI), relative wall thickness (RWT), trans mitral flow propagation velocity (Vp), TDI, and midwall shortening fraction (MWSF). Nocturnal dipping was defined as a reduction of diastolic BP (DBP) by >10% of systolic BP (SBP) when compared with the daytime values. Isolated systolic nondipping, is reduction of Results Among groups, the clinic SBP and DBP, daytime mean BP of 24-h ABPM, gender and body mass index were not statistically different. Augmentation pressure (AP), augmentation index (AI) showed statistically significant difference ( p = 0.008 and 0.021, respectively). Multivariate analysis showed that isolated diastolic non-dipping was correlated with arterial stiffness expressed as AI only in young group.