Changes in Bone Turnover Markers Associated With a Single Dialysis Session

Background. Chronic kidney disease (CKD) is associated with disturbances in mineral and bone metabolism, increasing fracture risk, particularly in advanced stages. Bone turnover markers (BTMs) such as bone alkaline phosphatase (BALP) and tartrate‐resistant acid phosphatase 5b (TRACP5b), as well as collagen‐derived markers including intact form of procollagen type I amino‐terminal propeptide (iPINP) and β‐cross‐linked C‐terminal telopeptide of type I collagen (β‐CTX‐I), are recommended to assess bone turnover. Although some BTMs are considered stable and independent of renal function, their behavior during dialysis sessions remains unclear. Methods. To assess the impact of dialysis techniques and membrane types, serum samples were collected pre‐ and post‐dialysis. BTM concentrations were analyzed using nonparametric statistics, and the clinical relevance of the observed changes was evaluated using the least significant change (LSC) thresholds. Results. BALP and TRACP5b showed minor fluctuations post‐dialysis, with changes remaining below their clinical significance thresholds. iPINP also showed limited variability. In contrast, β‐CTX‐I decreased significantly after hemodialysis, especially using high‐permeability membranes, with changes exceeding the LSC threshold. Conclusion. These findings suggest that BALP, TRACP5b, and PINP demonstrate robustness as BTMs in CKD patients undergoing dialysis. However, β‐CTX‐I is markedly affected by dialysis parameters and should be interpreted cautiously in this context.