Low Molecular Weight Iron Dextran Increases Fibroblast Growth Factor‐23 Concentration, Together With Parathyroid Hormone Decrease in Hemodialyzed Patients

Abstract

Fibroblast growth factor (FGF)-23 inhibits PTH production. Elevated FGF-23 and parathyroid hormone (PTH) levels are characteristic of hemodialyzed patients. Iron polymaltose was shown to increase FGF-23 concentration. The effect of intravenous low molecular weight iron dextran (LMID) on these hormones and bone metabolism has not been studied in hemodialysis (HD). Twelve HD patients were prospectively followed up for 3 weeks after a single infusion of LMID. Calcium, phosphate, FGF-23, PTH, degradation products of C-terminal telopeptides of type I collagen (CTX) and procollagen I N-terminal propeptide (PINP) were measured prior to, and at week 1 and week 3 after the LMID administration. FGF-23 increased significantly from 453.4 (68.6-3971.5) pg/mL at baseline to 971.8 (779.5-3361.4) pg/mL (P = 0.001) at week 1 and started to decrease toward the initial value at week 3. The changes were accompanied by a significant decline in PTH from 367.6 (21.4-1487.4) pg/mL at baseline to 315.7 (16.4-1339.8) pg/mL (P = 0.018) at week 1 and subsequently began to increase toward the initial values. Phosphate, calcium, CTX and PINP did not change over the study course. LMID causes an increase in FGF-23 concentration together with a decrease in PTH. Our study highlights a pathophysiological element, which may connect suppression of parathyroid glands with intravenous iron supplementation.

Ferric Citrate Decreases Fibroblast Growth Factor 23 and Improves Erythropoietin Responsiveness in Hemodialysis Patients

“…FGF23 levels in the latter studies were parallel to levels detected in murine models with CKD, supporting the hypothesis that elevation of FGF23 observed in CKD may contribute to the development of anemia [29]. Furthermore, iron deficiency anemia stimulates FGF23 synthesis [30, 31]. Although previous studies included only patients with iron deficiency, the present study included patients with and without iron deficiency.…”

Fibroblast growth factor is associated to left ventricular mass index, anemia and low values of transferrin saturation

“…But only in FCM group iFGF-23 increased temporarily and serum phosphorous is decreased 44 . Besides this in HD patients PTH suppression and rise in iFGF-23 level after IV low molecular weight ID treatment was observed 45 .…”

“…But in this study there was no data about the association of hemoglobin and iFGF-23 46 . Researchers think some carbohydrate components in iron preparations to inhibit FGF-23 degradation in osteocytes to cause a transient raise in iFGF-23 [44][45][46] . In another study iron isomaltose and FCM given intraperitoneally were shown to have no effect on plasma iFGF23 levels both in normal and uremic rats 47 .…”

Associations Between Intravenous Iron, Inflammation and FGF23 in Non-Dialysis Patients with Chronic Kidney Disease Stages 3-5

“…It is noteworthy that in chronic hemodialysis patients, IV low molecular weight iron dextran [34] or saccharate ferric oxide infusion [33] induced an increase in serum FGF23 and a decrease in PTH but without any significant changes of serum phosphate [34, 35]. …”