Prognostic Implication of Plasma Osteopontin Levels in Patients with Chronic Kidney Disease

Aims: To assess (a) plasma osteopontin (pOPN) in a cohort of chronic kidney disease (CKD) patients; (b) the relationship between pOPN and aortic calcification and stiffness, and (c) the association between pOPN and the overall and cardiovascular mortality risk. Methods: pOPN, the abdominal aortic calcification score and pulse wave velocity (PWV) were determined in 94 CKD patients (68 +/- 13 years; 60% males; 31% at CKD stages 2-3, 31% at stages 4-5, 38% at stage 5D), prospectively followed for mortality. Results: pOPN was higher in CKD patients than in controls. Interleukin (IL)-6 (r(2) = 0.086; p = 0.004), CRP (r(2) = 0.046; p = 0.038), iPTH (r(2) = 0.065; p = 0.014), albumin (r(2) = 0.210; p < 0.0001) and statin use (r(2) = 0.038; p = 0.059) were associated with pOPN. There was no association between pOPN and the aortic calcification score or PWV. During follow-up (969 +/- 405 days), 32 patients died. In crude analysis, pOPN>167 ng/ml predicted overall and cardiovascular mortality (p = 0.02 and 0.01, respectively), but this effect was lost after adjustment for albumin or IL-6. Conclusions: pOPN is elevated from the early stages of CKD onward. We found no associations between pOPN and the aortic calcification score or the PWV. The positive association between pOPN and clinical outcomes was dependent of the patients' inflammatory status. Copyright (C) 2010 S. Karger AG, Basel