Effects of different dialysate calcium concentrations on heart rate variability and serum ionized calcium levels in maintenance hemodialysis patients
Abstract
Aims: Heart rate variability (HRV), a marker of cardiac autonomic function, is suppressed in patients receiving maintenance hemodialysis (MHD) compared with the general population. However, data on modifiable dialysis-related factors influencing HRV remain limited. This study aimed to investigate the impact of different dialysate calcium concentrations on serum ionized calcium (iCa) levels and cardiac autonomic function, assessed by HRV, in MHD patients. Methods: This prospective observational study with repeated measures included patients receiving MHD. Baseline electrocardiography and transthoracic echocardiography were performed in all participants. Twenty-four–hour ambulatory electrocardiographic recordings were obtained using Holter monitors initiated immediately before the index hemodialysis (HD) session. The time domain measures of HRV were the standard deviation of all RR interval (SDNN), the mean of the standard deviation of all 5-minute RR intervals (SDNN index: SDNNI), the standard deviation of the average NN intervals over 5-minute segments (SDANN), and the square root of the mean difference between consecutive normal RR intervals (RMSSD). Serum iCa, magnesium, and potassium levels were measured at the beginning and at the end of the index HD session. Relative changes (Δ) in biochemical parameters were calculated as [(baseline value-4th hour value)]/baseline value. All clinical, biochemical, and HRV parameters were compared between groups stratified according to 1.25 mmol/L and 1.50 mmol/L calcium dialysate concentration. Results: A single 4-hour HD session using dialysate containing 1.25 mmol/L calcium was associated with a significant reduction in serum iCa levels and a greater relative change in iCa (∆iCa) compared with 1.50 mmol/L calcium dialysate. In the 1.25 mmol/L calcium dialysate group, all time-domain HRV parameters decreased, accompanied by greater relative changes. In contrast, treatment with 1.50 mmol/L calcium dialysate was related to increases in SDNNI, SDANN, and RMSSD values. After adjustment for potential confounders, multivariable regression analysis demonstrated that ∆iCa was independently associated with ∆SDANN. Conclusion: A single 4-hour HD session with 1.25 mmol/L calcium dialysate was associated with an acute decline in serum iCa levels and parallel changes in HRV indices, suggesting a potential link between dialysate calcium concentration and short-term autonomic modulation in MHD patients.
Keywords
References
- Himmelfarb J, Ikizler TA. Hemodialysis. N Engl J Med. 2010;363:1833-1845. doi:10.1056/NEJMra0902710
- Herzog CA. Sudden cardiac death and acute myocardial infarction in dialysis patients: perspectives of a cardiologist. Semin Nephrol. 2005;25:363-366. doi:10.1016/j.semnephrol.2005.05.003
- Herzog CA. Cardiac arrest in dialysis patients: taking a small step. Semin Dial. 2004;17(3): 184-185. doi:10.1111/j.0894-0959.2004.17318.x
- Rubinger D, Backenroth R, Sapoznikov D. Sympathetic nervous system function and dysfunction in chronic hemodialysis patients. Semin Dial. 2013;26(3):333-343. doi:10.1111/sdi.12093
- Ranpuria R, Hall M, Chan CT, Unruh M. Heart rate variability (HRV) in kidney failure: measurement and consequences of reduced HRV. Nephrol Dial Transplant. 2008;23(2):444-449. doi:10.1093/ndt/gfm634
- Chan CT. Heart rate variability in patients with end-stage renal disease: an emerging predictive tool for sudden cardiac death? Nephrol Dial Transplant. 2008;23(10):3061-3062. doi:10.1093/ndt/gfn280
- Osataphan N, Wongcharoen W, Phrommintikul A, Putchagarn P, Noppakun K. Predictive value of heart rate variability on long-term mortality in end-stage kidney disease on hemodialysis. PLoS One. 2023; 18(2):e0282344. doi:10.1371/journal.pone.0282344
- Genovesi S, Boriani G, Covic A, et al. Sudden cardiac death in dialysis patients: different causes and management strategies. Nephrol Dial Transplant. 2021;36(3):396-405. doi:10.1093/ndt/gfz182
Details
Primary Language
English
Subjects
Nefroloji
Journal Section
Research Article
Authors
Hatice Şahin
0000-0002-7146-4828
Türkiye
Haksun Ebinç
0000-0001-5362-5037
Türkiye
Ülver Derici
0000-0002-9741-6779
Türkiye
Publication Date
July 16, 2026
Submission Date
November 25, 2025
Acceptance Date
March 12, 2026
Published in Issue
Year 2026 Volume: 8 Number: 4






