Effect of ferric citrate hydrate on FGF23 and PTH levels in patients with non-dialysis-dependent chronic kidney disease with normophosphatemia and iron deficiency

Background In patients with normophosphatemia with chronic kidney disease (CKD), fibroblast growth factor 23 (FGF23) and parathyroid hormone (PTH) increase urinary phosphate excretion while maintaining serum phosphate within the normal range. Recent reports have shown that, in this stage, phosphate binders do not decrease serum FGF23 and PTH levels. Iron deficiency promotes transcription of FGF23 and iron-supplementation for iron deficiency decreases serum FGF23 levels. We hypothesized that ferric citrate hydrate, an iron-based phosphate binder, will decrease serum FGF23 levels in patients with non-dialysis-dependent CKD with normophosphatemia and iron deficiency.