Alkaline Phosphatase, iPTH and Bone Turnover Markers in Chinese Advanced Chronic Kidney Disease Patients

Clinicians may use several biochemical markers of bone turnover to assess or guide the care of patients with chronic kidney disease (CKD). The aims of this study are to describe changes and correlations of markers of bone remodeling in patients with different stages of CKD.

A total of 317 Chinese patients with advanced CKD (stage 3-5) were enrolled. We measured serum levels of intact-parathyroid hormone (iPTH), N-terminal midfragment (N-MID) osteocalcin, procollagen type 1 amino-terminal propeptide (P1NP), β-isomerized C-terminal telopeptide (β-CTx), total alkaline phosphatase (ALP), and 25-hydroxyvitamin D (25[OH]D).

Levels of iPTH, N-MID osteocalcin, P1NP, and β-CTx and serum phosphorus were significantly different among patients with different stages of CKD. Serum levels of ALP and 25(OH)D were higher in hemodialysis (HD) patients than in peritoneal dialysis (PD) patients. Levels of ALP, osteocalcin, and P1NP were significantly higher in dialysis patients than in non-dialysis patients. Correlations between the levels of iPTH, ALP, N-MID os- teocalcin, P1NP, and β-CTx were statistically significant but weak. There was no correlation between 25(OH)D and iPTH or ALP.

Our results suggest that measurement of N-MID osteocalcin, P1NP, β-CTx, and iPTH may be useful for assessment of CKD-mineral bone disorder (MBD) in patients with CKD.