Cystatin C is better than albuminuria as a predictor of pulse wave velocity in hypertensive patients.

ABSTRACT

INTRODUCTION: Arterial stiffness is important in the evaluation of the cardiovascular risk in both general population and hypertensive patients. In this study, we aimed to investigate the associations of both serum cystatin C levels and albuminuria with arterial stiffness in healthy controls and hypertensive patients. PATIENTS AND METHODS: Seventy-six healthy controls (male/female = 44/32) and 76 hypertensive patients (male/female = 43/33) were enrolled. Arterial stiffness parameters such as augmentation index (AIx) and pulse wave velocity (PWV) were non-invasively measured with the Arteriograph (Tensiomed Ltd., Budapest, Hungary). RESULTS: AIx (31.92 ± 14.31 vs. 27.95 ± 11.03, p = 0.03) and PWV (9.84 ± 1.62 vs. 8.87 ± 2.04, p < 0.001) were significantly higher in hypertensive patients compared to healthy controls. Patients with microalbuminuria had significantly higher AIx (43.47 ± 9.91 vs. 30.37 ± 14.13, p = 0.002) and higher serum cystatin C levels [0.76 (0.67-0.95) vs. 0.68 (0.62-0.78) mg/L, p = 0.03]. In the hypertensive group, AIx was significantly correlated with PWV (r = 0.519, p < 0.001), glomerular filtration rate (cystatin C) (r = -0.438, p = 0.003), mean arterial pressure (MAP) (r = 0.288, p = 0.015) and urinary albumin-creatinine ratio (ACR) (r = 0.386, p = 0.004). PWV was associated with serum cystatin C (r = 0.442, p = 0.003) and MAP (r = 0.377, p = 0.001). In the linear regression analysis (model r = 0.577, p = 0.006) for the prediction of PWV in hypertensive patients, MAP, urinary ACR, age and serum cystatin C levels were included as independent variables. Cystatin C was found to be the significant determinant of PWV in hypertensive patients. CONCLUSION: Multivariate analysis revealed that serum cystatin C but not albuminuria was significantly associated with PWV in hypertensive patients. Serum cystatin C may be better than albuminuria as a predictor of arterial stiffness in hypertensive patients.