Purpose: The dismal combination of hypertension and chronic kidney disease potentiates both cardiovascular disease and loss of renal function. Research points to the importance of arterial and left ventricular stiffening in this process but few studies have compared aspects of central and peripheral hemodynamics in relation to renal function in hypertension.
Materials and methods: We investigated 107 hypertensive individuals with renal function ranging from normal to severe dysfunction with pulse wave analysis to obtain central blood pressures (BP), augmentation index, carotid-femoral and carotid-radial pulse wave velocity (cfPWV, crPWV), aortic-to-brachial stiffness mismatch (cfPWV/crPWV), endothelial function by forearm flow-mediated vasodilation and myocardial microvascular function by subendocardial viability ratio, and indices of left ventricular structure (left ventricular mass index and relative wall thickness, RWT) and diastolic function (left atrial volume index, E/A, and E/é).
Results: Mean age was 58 years, BP 149/87 mm Hg, 9% had cardiovascular disease, and 31% were on antihypertensive treatment. Mean estimated glomerular filtration rate (eGFR) was 74 (range 130-21) ml/min × 1.73 m2. Whereas cfPWV and cfPWV/crPWV were independently related to eGFR (r = -0.20, p = 0.002, r = -0.16, p = 0.01), central diastolic BP (r = 0.21, p = 0.04), RWT (r = -0.34, p = 0.001), E/é (r = -0.39, p < 0.001) and E/A (r = 0.27, p = 0.01) were related to eGFR in bivariate correlations, but these findings were not retained in multivariate analyses. Remaining markers of hypertensive heart disease and measures of microvascular function were not related to eGFR.
Conclusion: Increased aortic stiffness and aortic-to-brachial stiffness mismatch are independently related to reduced eGFR in hypertensive patients, suggesting an important role for aortic stiffness in the evolution of hypertension-mediated renal dysfunction. Aortic stiffness and aortic-brachial stiffness mismatch may be useful early markers to find hypertensive patients at risk for decline in renal function.
Keywords: Hypertension; aortic stiffness; chronic kidney disease; echocardiography; endothelial function; hypertensive heart disease; pulse wave analysis; renal function.