Association Between Circadian Hemodynamic Characteristics and Target Organ Damage in Patients With Essential Hypertension

Abstract

Background: This study investigated the association between circadian hemodynamic characteristics and asymptomatic hypertensive organ damage.

Methods: Circadian hemodynamics, including 24-hour brachial and aortic systolic blood pressure (SBP), pulse wave velocity (PWV), augmentation index (AIx@75), cardiac index, and total vascular resistance (TVR), were evaluated using an oscillometric device, Mobil-O-Graph, in 284 essential hypertensive patients (67.8 ± 16.0 years, 54% female). Hypertensive target organ damage (TOD), namely carotid wall thickening, left ventricular hypertrophy, and albuminuria, was assessed in all patients.

Results: Office SBP and 24-hour brachial and aortic SBP all increased with increasing number of organs involved (all P < 0.01 for trend). After multivariate logistic regression analysis, 24-hour brachial SBP (odds ratio [OR] = 1.04 for 1 mm Hg increase, P < 0.001) as well as aortic SBP (OR = 1.03 for 1 mm Hg increase, P < 0.05) maintained significance. Percent decrease during nighttime in brachial SBP, PWV, and TVR, but not cardiac index, showed a significant graded relationship with the number of organs involved. In a multivariate stepwise regression model, the nighttime values of brachial SBP, PWV, and TVR emerged as independent predictors of the presence of TOD.

Conclusion: In essential hypertension, 24-hour aortic SBP could be a marker of subclinical TOD, and further, the blunted nocturnal BP reduction in TOD patients might be mediated by disturbed circadian hemodynamic variations in aortic SBP, vascular resistance, and arterial stiffness.

Keywords: ambulatory blood pressure monitoring; blood pressure; central blood pressure; hemodynamic characteristics; hypertension; target organ damage.