CST3 and chronic kidney disease: A univariate analysis revealed a significant negative correlation between the RI, as detected by Doppler echography, and the eGFR (P < 0.0001, r = - 0.6062; Fig 1B); similar findings have been reported in CKD patients [30, 31] Significant correlations were also observed between the RI and age (P < 0.0001, r = 0.5404; Fig 1A), albuminuria (P = 0.0100, r = 0.2902; Fig 1C), cystatin C (P < 0.0001, r = 0.6920; Fig 1D), baPWV (P < 0.0001, r = 0.4410; Fig 1E), and maximum IMT (P = 0.0005, r = 0.3538; Fig 1F).