Association of Arterial Stiffness Indexes, Determined From Digital Volume Pulse Measurement and Cardiovascular Risk Factors in Chronic Kidney Disease

BACKGROUND Progression of atherosclerosis with increased arterial stiffness is associated with increased cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD). Compliance index (Cl) derived from digital volume pulse (DVP), measuring the relationship between volume and pressure changes in fingertip, can evaluate the local arterial stiffness. The purpose of this study was to measure the stiffness of different arteries and determine the relationships of CI-DVP with clinical characteristics and renal function in CKD patients. METHODS This cross-sectional pilot study included 186 CKD and 46 healthy subjects. Evaluation of different arterial stiffness was performed by DVP using dual-channel photoplethysmography and measured as Cl (CI-DVP) and pulse wave velocity (PWV)-DVP. RESULTS CKD patients had lower CI-DVP and higher PWV-DVP than that in the healthy group. There was a trend of stepwise decrease in CI-DVP and increase in PWV-DVP related to the advance of CKD from early to late stage. Decrease of CI-DVP was associated with the increase in number of cardiovascular risk factors. Multivariate linear regression analysis revealed that CI-DVP (B = 4.59, P < 0.01) was independently associated with estimated glomerular filtration rate (eGFR). Male gender, eGFR, and systolic blood pressure (BP) were independent determinants for CI-DVP (B = -0.25, P = 0.01; B = 0.007, P = 0.03; and B = -0.03, P < 0.0001; whole model R-2 = 0.28, P < 0.0001). CONCLUSIONS Our data demonstrate a significant association between CI-DVP, a new surrogate marker of arterial stiffness different from PWV, and renal function and cardiovascular risk factors in CKD patients.