FGF23 and chronic kidney disease: As a phosphaturic hormone, FGF23 is stimulated by decreased renal phosphate excretion and subsequent hyperphosphatemia due to a declining glomerular filtration rate in patients with CKD [25]; therefore, it is reasonable that these markers related to iP homeostasis (cCa, iP, ALP, and iPTH) were associated with serum FGF23.