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Abstract: FR-PO792

High Pretransplant FGF-23 Level Is Associated With Poor Graft Survival and Persistent Vitamin D Insufficiency in Kidney Transplant Patients

Session Information

Category: Transplantation

  • 2002 Transplantation: Clinical


  • Ryu, Jung-hwa, Ewha Womans University Seoul Hospital, Seoul, Korea (the Republic of)
  • Koo, Tai yeon, Korea University, Seongbuk-gu, Seoul , Korea (the Republic of)
  • Kim, Hyo Jeong, Yonsei University College of Medicine, Seodaemun-gu, Seoul , Korea (the Republic of)
  • Heo, Ga Young, Yonsei University College of Medicine, Seodaemun-gu, Seoul , Korea (the Republic of)
  • Yang, Jaeseok, Yonsei University College of Medicine, Seodaemun-gu, Seoul , Korea (the Republic of)

Group or Team Name

  • KNOW-KT Study group

Vitamin D [25(OH)D] insufficiency and FGF-23 elevation in chronic kidney disease (CKD) is usually ameliorated after kidney transplantation (KT). However, post-transplant vitamin D insufficiency are still associated with poor graft outcome. This study aimed to investigate the effect of pretransplant FGF-23 level on post-transplant vitamin D status and clinical outcomes.


The KoreaN cohort study for Outcome in patients With Kidney Transplantation (KNOW-KT) is a multicenter, observational cohort study. Four hundred subjects for whom serum FGF-23 measurement was available, were included in this study. Annual serum 25(OH)D and clinical outcomes; all-cause mortality, cardiovascular event, graft survival, and fracture were assessed according to baseline FGF-23 levels.


Median follow-up duration was 6.5 years. Serum 25(OH)D3 levels were increased after KT (before KT, 12.6±7.4; 1 year after KT, 22.6±6.4; 3 years after KT, 24.3±5.8 ng/mL). However, they were declined to 20.9±9.2 ng/mL at 7 years after KT. Vitamin D deficiency was present in 79.1% just before KT, then it was decreased to 30.8% at 3 years after KT, whereas it was increased 37.8% at 6 years after KT. Serum FGF-23 level was decreased after KT [2140.6 (391-9277) pg/ml before KT vs. 50.0 (23.6-94.6) pg/ml at 3 years after KT, P=0.001]. The FGF-23 showed negative correlation with serum vitamin D levels. When we categorized subjects into tertile according to baseline GFG-23 level (low, middle, high FGF-23 groups), the 25(OH)D3 in the low baseline FGF-23 group was lowest at any point during follow-up. High baseline FGF-23 level was a risk factor for poor graft survival (HR 5.882, 95% C.I.; 1.443-23.976, P=0.022).


Increased FGF-23 could interfere vitamin D activation even after KT and is a risk factor for poor graft survival.