Abstract: FR-PO0484
Joint Association of Body Size and Convection Volume of Hemodiafiltration with All-Cause Mortality
Session Information
- Dialysis: Hemodiafiltration, Ultrafiltration, Profiling, and Interdialytic Symptoms
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Zhang, Yan, Renal Research Institute, New York, New York, United States
- Winter, Anke, Renal Research Institute, New York, New York, United States
- Ficociello, Linda, Renal Research Institute, New York, New York, United States
- Vernooij, Robin W.m., University Medical Centre Utrecht, Utrecht, Netherlands
- Usvyat, Len A., Renal Research Institute, New York, New York, United States
- Stuard, Stefano, Fresenius Medical Care Italia SpA, Palazzo Pignano, Lombardia, Italy
- Blankestijn, Peter J., University Medical Centre Utrecht, Utrecht, Netherlands
Background
Emerging evidence suggests that hemodiafiltration (HDF) improves patient survival in a dose-dependent manner relative to convection volume (CV). The delivered CV is determined by multiple factors including patient body size. This study examined the joint association of body size and achieved CV with all-cause mortality among HDF patients.
Methods
We included 42,077 patients treated with post-dilution HDF in Fresenius Medical Care NephroCare Clinics in 2019-2022. We performed a Cox proportional hazard regression analysis, modelling post-dialysis body weight and CV as a bivariate spline function to estimate their joint associations with all-cause mortality (hazard ratios calculated with 75kg and 23L as reference values). The model was adjusted for demographics, kidney failure etiology, comorbidities, dialysis vintage, vascular access, systolic blood pressure, blood flow rate, and treatment time. The joint associations were also assessed across body mass index (BMI) categories.
Results
A CV increase was associated with a reduced mortality risk, with weight-dependent effect size variations. At equivalent CV levels, mortality risk varied across different body weight (Fig. 1a). Joint associations differed across BMI categories (Fig. 1b-1f), with the least joint impact in underweight group. Evaluating mortality risk as a function of CV at a constant body weight of 70kg across BMI categories, L-shaped curve was observed among underweight patients and U-shaped curves among other BMI categories (Fig. 2).
Conclusion
Our study suggests complex nonlinear associations of body size and CV with all-cause mortality in HDF patients. Higher CV appears to be associated with lower mortality with body size dependent effect variations, highlighting the importance of individualized HDF dosing strategies to optimize patient outcomes.