Sevelamer Hydrochloride and Calcium Bicarbonate Reduce Serum Fibroblast Growth Factor 23 Levels in Dialysis Patients

Abstract

Fibroblast growth factor 23 (FGF23) is a member of the fibroblast growth factor superfamily which displays a strong phosphaturic action and an inhibition of vitamin D 1-alpha hydroxylase activity. Fourty-six patients undergoing maintenance hemodialysis therapy participated in the study. They were randomly divided into 2 groups, and treated with either 3 g sevelamer hydrochloride+3 g of calcium bicarbonate (CaCO3), or 3 g of CaCO3 alone. Serum FGF23 levels were determined by a sandwich enzyme-linked immunosorbent assay (ELISA) system that detects the intact form of FGF23 molecules. Although the serum inorganic phosphate (Pi) levels were comparable before treatment, the levels were significantly lower in the patients treated with sevelamer hydrochloride+CaCO3 than those with CaCO3 alone after 4 weeks of treatment (P<0.05). Serum FGF23 levels significantly decreased after 4 weeks of the treatment with sevelamer hydrochloride+CaCO3 from the pretreatment levels (P<0.05), while no changes were found in the patients treated with CaCO3 alone. Thus, the use of sevelamer hydrochloride and CaCO3 reduced serum FGF23 levels in dialysis patients presumably through inhibiting phosphate load into the intestine.

FGF-23 Associates with Death, Cardiovascular Events, and Initiation of Chronic Dialysis

“…The observations that phosphorus loading increases serum FGF-23 concentrations in healthy subjects and that the use of phosphate binders decreases serum FGF-23 concentrations in chronic dialysis patients provide a plausible mechanistic explanation for the association between the early use of phosphate binders and improved clinical outcomes. 25,26,27 Further interventional trials are necessary to determine if the reduction of plasma FGF-23 concentrations indeed provides cardio-and renoprotective effects in CKD patients.…”

Serum Fibroblast Growth Factor-23 Levels and Progression of Aortic Arch Calcification in Non-Diabetic Patients on Chronic Hemodialysis

“…Secondly, elevated FGF-23 lower calcitriol levels via the inhibition of 25-hydroxyvitamin D3 1--hydroxylase. Given the strong evidence for vitamin D deficiency as a non-traditional cardiovascular risk factor in HD patients 32) , increased FGF-23 levels may indirectly exert a harmful effect on AoAC by inducing hypovitaminosis D. Thirdly, a previous report suggests that oral P binders might affect FGF-23 levels 33) . Even though there was no significant difference in serum FGF-23 levels among the three groups, most patients in the three groups had taken vitamin D and sevelamer, which could have affected serum FGF-23 levels in this study.…”

Effects of Cinacalcet and Concurrent Low-Dose Vitamin D on FGF23 Levels in ESRD

“…FGF23 levels were measured in triplicate using the full-length intact human FGF23 ELISA (Kainos, Tokyo, Japan), as used by many other investigators (10,11,17,26). Ca, P, and PTH were measured as described elsewhere (25).…”