Effects of phosphate binders on bone biomarkers and bone density in haemodialysis patients.

Aim: The incidences of osteoporosis, fracture and vascular calcification increase concordantly with the progression of chronic kidney disease (CKD). CKD-mineral bone disease (CKD-MBD) induced by hyperphosphatemia is a major pathophysiologic mechanism. The effects of phosphate binders on bone turnover biomarkers and bone mineral density (BMD) in haemodialysis patients are still inconclusive. Our aim is to demonstrate the effects of these phosphate binders on different aspects of CKD-MBD.

Methods: We conducted a prospective cohort of 65 haemodialysis patients to investigate the effect of 12-month monotherapy of phosphate binders composing calcium-based phosphate binders (CPB) or non-calcium-based phosphate binders (NCPB), including sevelamer and lanthanum, on bone turnover biomarkers and BMD changes. The performance of bone turnover biomarkers to predict low BMD was attentively determined.

Results: When compared with CPB, NCPB use was associated with higher levels of bone turnover biomarkers. NCPB was also associated with lower BMD at lumbar and distal radius. Total procollagen type 1N-terminal propeptide (P1NP), bone-specific alkaline phosphatase (BALP), and tartrate-resistant acid phosphatase 5b (TRAP5b) provided the best performance for diagnosing low BMD in haemodialysis patients.

Conclusion: Switching from CPB to NCPB might increase bone biomarkers and prevent the development of adynamic bone disease. On the contrary, NCPB should be cautiously used in haemodialysis patients who already had low BMD. P1NP, BALP and TRAP5b could be used to guide the appropriate management, including anti-resorptive and anabolic medications, and predict low BMD in haemodialysis patients treated with phosphate binders.