Abstract: TH-PO0454
Association of Predialysis and Postdialysis Phosphorous Levels with Prognosis in Extended-Hours Hemodialysis
Session Information
- Hemodialysis: Novel Markers and Case Reports
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Author
- Ishikawa, Shigefumi, Nagoya Daigaku, Nagoya, Aichi Prefecture, Japan
Background
Extended-hours hemodialysis is effective for removing phosphate; however, it could lead to very low phosphorous levels after hemodialysis, which might worsen prognosis. This study aimed to clarify the association between serum pre- and post-dialysis phosphorous levels and prognosis in patients undergoing extended-hours hemodialysis.
Methods
We enrolled 451 hemodialysis patients with at least one year history of extended-hours hemodialysis and available baseline data at one year after initiation of extended-hours hemodialysis. The association of pre- and post-dialysis phosphorous levels with mortality was evaluated using baseline, time-dependent, and time-averaged Cox models. Non-linear associations were assessed using restricted cubic splines. We analyzed the longitudinal trends of pre- and post-dialysis phosphorous levels using mixed-effects models.
Results
The median follow-up period was 5.75 years, with 123 deaths (incidence rate: 4.4 per 100 person-years). Mean pre- and post-dialysis phosphorous levels were 5.1 mg/dL and 2.7 mg/dL, respectively. In the time-averaged model, pre-dialysis phosphorous levels ≥6.0 mg/dL were associated with increased mortality, and in the time-dependent model, post-dialysis phosphorous levels ≤2.5 mg/dL were associated with increased mortality. Longitudinal analysis showed a gradual increase in pre-dialysis phosphorous levels, while post-dialysis phosphorous levels remained stably above 2.5 mg/dL.
Conclusion
In extended-hours hemodialysis patients, higher pre-dialysis phosphorous levels were associated with poor long-term prognosis, and lower post-dialysis phosohorous levels was associated with poor short-term prognosis. Stable maintenance of post-dialysis phosphorous levels over time may contribute to improved prognosis.
Funding
- NIDDK Support