Abstract: SA-PO1072
Differences in Intact Fibroblast Growth Factor 23 Between Extended-Hours and Conventional Hemodialysis
Session Information
- Kidney Replacement Therapy and Care Delivery Innovations
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Yamada, Takumi, Nagoya Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Nagoya, Aichi Prefecture, Japan
- Nishibori, Nobuhiro, Nagoya Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Nagoya, Aichi Prefecture, Japan
- Okazaki, Masaki, Shinseikai Daiichi Byoin, Nagoya, Aichi Prefecture, Japan
- Imaizumi, Takahiro, Nagoya Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Nagoya, Aichi Prefecture, Japan
- Kasuga, Hirotake, Nagoya Kyoritsu Byoin, Nagoya, Aichi Prefecture, Japan
- Kaneda, Fumika, Iryo Hojin Kamome Clinic, Iwaki, Fukushima Prefecture, Japan
- Maruyama, Shoichi, Nagoya Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Nagoya, Aichi Prefecture, Japan
Background
FGF23 is involved in mineral bone disorder and prognosis in dialysis patients. However, differences in intact FGF23 (iFGF23) between dialysis modalities and the factors explaining these differences remain unclear. This study compared iFGF23 levels between extended-hours and conventional HD and examined factors related to modality-specific differences.
Methods
A multicenter cohort of 169 patients on extended-hours HD and 187 on conventional HD was analyzed. Extended-hours HD was defined as a total dialysis treatment time of ≥18 hours per week; nocturnal HD patients were excluded. Associations with iFGF23 were evaluated using multivariable linear regression, restricted cubic spline models, and mediation analysis with active vitamin D use as the mediator.
Results
iFGF23 levels were lower in extended-hours HD (5356 vs. 5865 pg/mL, P=0.05). Phosphate levels were similar (5.44 vs. 5.40 mg/dL, P=0.74), and serum calcium was slightly lower in extended-hours HD (9.0 vs. 9.2 mg/dL, P=0.002). Active vitamin D use was significantly lower in extended-hours HD (55% vs. 87%, P<0.001). In multivariable analysis, extended-hours HD was significantly associated with lower iFGF23 (β = −0.43, P=0.004). After adjusting for clinical covariates including active vitamin D use, the association between extended-hours HD and iFGF23 was attenuated and no longer significant (β = −0.21, P=0.18), whereas active vitamin D use remained strongly associated with higher iFGF23 (β = 0.60, P<0.001). Mediation analysis indicated that 44.5% of the association between extended-hours HD and lower iFGF23 was explained by differences in vitamin D use.
Conclusion
In this study, iFGF23 levels were lower in patients undergoing extended-hours HD, potentially due to less frequent active vitamin D use. This finding suggests that lower active vitamin D requirements—and the resulting reduction in FGF23—may be one mechanism underlying the cardiovascular and survival benefits reported with extended-hours HD.