ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: TH-PO192

Effect of Ferric Citrate Hydrate on FGF23 and Serum α-Klotho in Hemodialysis Patients with Hyperphosphatemia and Controlled Serum Phosphate Levels: ASTRIO Study, Supplementary Analysis

Session Information

Category: Bone and Mineral Metabolism

  • 402 Bone and Mineral Metabolism: Clinical

Authors

  • Yokoyama, Keitaro, Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
  • Fukagawa, Masafumi, Tokai University School of Medicine, Isehara, KANAGAWA, Japan
  • Nakayama, Masaaki, St Luke''s International Hospital, Tokyo, Japan
  • Kyoko, Ito, Torii Pharmaceutical Co., Ltd, Tokyo, Japan
  • Hanaki, Koji, Japan Tobacco Inc., Tokyo, Japan
  • Hirakata, Hideki, Fukuoka Renal Clinic, Fukuoka City, Japan
Background

Elevated serum Fibroblast Growth Factor (FGF) 23 level is an independent risk factor for the progression to ESRD, and high FGF23 levels are reportedly associated with cardiovascular events. There is growing interest in α-klotho, a co-receptor for FGF23, as a biomarker of kidney function, because low α-klotho levels have been associated with adverse kidney disease outcome. However, the effect of phosphate binders (PBs) on α-klotho has not been extensively evaluated.

Methods

ASTRIO was a prospective, randomized, multicenter, 24-week study. 93 HD patients who had been taking non-iron based PBs were randomized to Ferric Citrate Hydrate (FC) group (n=45) or Control group (n=48). In Control, patients maintained treatment with their existing PBs. Serum P and Hb were controlled within 3.5 to 6.0 mg/dL and 10.0 to 12.0 g/dL, respectively. The primary endpoint was change in ESA dose; we also evaluated serum FGF23 and α-klotho.

Results

Serum P was maintained in both groups. C-terminal FGF23 (cFGF23) significantly decreased in FC compared to Control (p=0.04). There were no statistical differences in the changes in intact FGF23 (iFGF23) and α-klotho between groups. Serum ferritin and TSAT were significantly increased in FC compared to Control.

Conclusion

In this study, while there was no difference in the change of serum P between the groups, cFGF23 significantly decreased in FC compared to Control, but did not change iFGF23 and α-klotho.

ParameterFC (N=40)
Mean (SD) Change
(from baseline to EOT**)
Control (N=42)
Mean (SD) Change
(from baseline to EOT**)
Adjusted Mean
Difference (FC minus Control)
p-value
P (mg/mL)0.24 (1.59)-0.17 (1.53)0.550.06
Ferritin (ng/mL)79.0 (81.5)2.9 (79.3)79.5<0.01
TSAT (%)8.6 (12.1)0.5 (11.8)9.0<0.01
cFGF23 (pg/mL)*-0.2 (0.8)0.2 (0.8)0.70.04
iFGF23 (pg/mL)*-0.1 (0.8)0.1 (0.9)0.80.33
α-klotho (pg/mL)2.0 (91.5)-8.9 (145.3)-11.10.58

*Logarithmic transformation, **End of treatment