Mo795calcium balance and ckd-mbd parameters differences of citrate vs. acetate dialysate

Abstract Background and Aims Dialysate composition is an essential feature of hemodialysis treatment. The use of acetate as the dialysate buffer and its calcium concentration are still topics of debate. Calcium transfer during dialysis sessions is related to short-term (hemodynamic tolerance and arrhythmias) and long-term effects (cardiovascular calcification and mortality). This study aims to identify the potential benefits derived from acetate-free dialysis by using citrate as a buffer in terms of calcium balance and CKD-MBD biomarkers. Method We performed a prospective crossover study that analyzed 24 dialysis sessions, 12 with each dialysate buffer, on every patient. Ionized calcium and CKD-MBD parameters were analyzed with each acidifier. Both dialysates had a calcium concentration of 1.5 mml/L. The remaining hemodialysis patients’ parameters were unchanged during the study period. Results No differences were found between pre-dialytical ionized calcium (iCa) (1,11 ± 0,12 vs. 1,08 ± 0,12 mmol/L) in both groups. However, we identified a significant iCa increase in the sessions were acetate dialysate was used, both in immediate (1,29 ± 0,07 mmol/L) and in 30-minutes post-dialytical blood analysis (1,22 ± 0,07 mmol/L). Whereas iCa levels remained stable during the immediate (1,07 ± 0,06 mmol/L) and 30-minutes post-dialytical analysis (1,08 ± 0,11 mmol/L) when using citrate. On the other hand, pre-dialysis albumin-corrected total calcium was higher with acetate (8,9 ± 0,6 vs. 8,31 ± 0,75 mg/dL, p = 0,003) and PTH was lower with acetate (169 vs. 267 pg/mL, p < 0,001). Conclusion Acetate-free dialysis using citrate as an acidifier stabilizes iCa levels during dialysis sessions while maintaining a neutral or negative effect in calcium balance. This analytical benefit may translate into better cardiovascular long-term outcomes.