Open Access Highly Accessed Research article

Cinacalcet lowering of serum fibroblast growth factor-23 concentration may be independent from serum Ca, P, PTH and dose of active vitamin D in peritoneal dialysis patients: a randomized controlled study

Hyo Jin Kim1, Hyunsuk Kim1, Nara Shin1, Ki Young Na2, Yong Lim Kim3, Daejung Kim4, Jae Hyun Chang5, Young Rim Song6, Young-Hwan Hwang7, Yon Su Kim1, Curie Ahn1, Joongyub Lee8, Kook-Hwan Oh1* and Representing the Cinacalcet stUdy for Peritoneal Dialysis Patients In Double Arm on the Lowering Effect Of iPTH Level (CUPID) Study Group

Author Affiliations

1 Department of Internal Medicine, Seoul National University, Seoul, Korea

2 Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam-si, Gyeonggi-do, Korea

3 Department of Internal Medicine, Kyungpook National University, Daegu, Korea

4 Department of Internal Medicine, Sungkyunkwan University, Seoul, Korea

5 Department of Internal Medicine, Gachon University, Incheon, Korea

6 Department of Internal Medicine, Hallym University, Seoul, Korea

7 Department of Internal Medicine, Eulji University, Seoul, Korea

8 Medical Research Collaborating Center, Seoul National University Hospital, Seoul, Korea

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BMC Nephrology 2013, 14:112  doi:10.1186/1471-2369-14-112

Published: 25 May 2013



Elevated serum level of fibroblast growth factor-23 (FGF23) is associated with adverse outcomes in dialyzed patients.


The CUPID study compared the efficacy of a cinacalcet-based regimen with conventional care (vitamin D and P binders) for achieving the stringent NKF-K/DOQI targets for peritoneal dialysis (PD) patients. Additionally, we analyzed change in FGF23 levels between two treatments to explore the cinacalcet effect in lowering FGF23.


Multicenter, open-labeled, randomized controlled study.


Seven university-affiliated hospitals in Korea.


Overall, 66 peritoneal dialysis patients were enrolled.


Sixty six patients were randomly assigned to treatment with either cinacalcet + oral vitamin D (cinacalcet group, n = 33) or oral vitamin D alone (control group, n = 33) to achieve K/DOQI targets. CUPID included a 4-week screening for vitamin D washout, a 12-week dose-titration, and a 4-week assessment phases. We calculated mean values of iPTH, Ca, P, Ca x P, during assessment phase and final FGF23 to assess the outcome.

Main outcome measures

Achievement of >30% reduction of iPTH from baseline (primary) and FGF23 reduction (secondary).


72.7% (n = 24) of the cinacalcet group and 93.9% (n = 31) of the control group completed the study. Cinacalcet group received 30.2 ± 18.0 mg/day of cinacalcet and 0.13 ± 0.32 μg/d oral vitamin D (P < 0.001 vs. control with 0.27 ± 0.18 μg/d vitamin D). The proportion of patients who reached the primary endpoint was not statistically different (48.5% vs. 51.5%, cinacalcet vs. control, P = 1.000). After treatment, cinacalcet group experienced a significant reduction in FGF23 levels (median value from 3,960 to 2,325 RU/ml, P = 0.002), while an insignificant change was shown for control group (from 2,085 to 2,415 RU/ml). The percent change of FGF23 after treatment was also significantly different between the two groups (− 42.54% vs. 15.83%, P = 0.008). After adjustment, cinacalcet treatment was independently associated with the serum FGF23 reduction.


Cinacalcet treatment was independently associated with the reduction of FGF23 in our PD patients.

Trial registration

Controlled trials NCT01101113

Cinacalcet; Fibroblast growth factor 23; Peritoneal dialysis