Study on the relationship of serum fetuin-A concentration with aortic stiffness in patients on dialysis.

BACKGROUND: An increase in aortic stiffness, as reflected by an increase in pulse wave velocity (PWV) or aortic augmentation index (AI) is an important predictor of cardiovascular mortality in dialysis patients. Dysregulation of calcification inhibitors, such as fetuin-A, is involved in vascular pathology in dialysis patients and fetuin-A is inversely related to mortality in dialysis patients. In this study, the relation between serum fetuin-A concentration and parameters of aortic stiffness was investigated in patients with end-stage renal disease. METHODS: In a cross-sectional study we included 131 dialysis patients, aged 62+/-14 years (33 on peritoneal dialysis and 98 on haemodialysis), and 41 controls, aged 60+/-8 years. Time-averaged pre-dialysis values of serum albumin, Ca, P and intact parathyroid hormone were included in multiregression analysis, as were high-sensitivity C-reactive protein (hsCRP), fetuin-A, age, mean arterial pressure (MAP) and dialysis modality. PWV and AI were measured with the SphygmoCor device. RESULTS: Mean fetuin-A concentration in dialysis patients (0.63+/-0.16 g/l) did not differ from controls (0.63+/-0.11 g/l). Median hsCRP levels in dialysis patients were higher compared with controls (4.0 vs 1.9 mg/l; P<0.0001). PWV but not AI was higher in dialysis patients than in controls (9.9 vs 7.9 m/s; P<0.0001). In univariate analysis in dialysis patients, fetuin-A levels were inversely related to both PWV (r = - 0.25, P = 0.007) and AI (r = - 0.26, P = 0.006), respectively. However, after correction for age, gender, MAP and diabetes mellitus, this relation lost statistical significance. CONCLUSIONS: In a dialysis population with a relatively low level of inflammatory activity, the soluble calcification inhibitor fetuin-A could not be identified as an independent predictor of aortic stiffness as measured with PWV and AI.