Evaluation of different bone markers in hemodialyzed patients

Background: Routinely, nephrologists rely on different biochemical markers like intact PTH (iPTH), bone-specific alkaline phosphatase (BALP), plasmatic calcium and phosphate. The aim of the present study was to evaluate different other bone markers like N-terminal propeptide of type I procollagen (PINP), active isoform 5b of the tartrate-resistant acid phosphatase (TRAP 5b) and beta-crossLaps (R) (CTXS) as well as full-length PTH (wPTH), presumed non-(1-84) PTH, and their ratio in the diagnosis of renal osteodystrophy with high and low turnover. We also determined 25 hydroxyvitamin D (25VTD), 1-25 dihydroxyvitamin D and homocystein (HCY). Methods: We performed those parameters on 73 patients with end-stage renal disease according to the manufacturers' instructions. Results: There were very strong correlations between the bone markers concentrations, particularly between BALP and PINP (r=0.953). We did not observe any correlation between the ratio whole PTH/non-(1-84) PTH and any of the usual bone markers. This ratio was significantly (p < 0.05) higher in low and high bone turnover patients than in normal patients according to the K/DOQI. We found a correlation between low levels of 25VTD and high levels of HCY Conclusions: BALP offers the best clinical and analytical profile as the easier marker of choice in hemodiallyzed patients for the diagnosis of bone disease. (c) 2006 Elsevier B.V All rights reserved