[Disturbance of phosphorus metabolism in chronic kidney disease].

The kidney plays a central role in the maintenance of phosphorus homeostasis. Thus disturbance of phosphorus metabolism develops in most patients with chronic kidney disease (CKD) . Hyperphosphatemia typically occur in advanced CKD patients of whose glomerular filtration rate is <30 ml/min, whereas in early-stage CKD normophosphatemia is maintained by increased secretion of fibroblast growth factor-23 (FGF-23) and parathyroid hormone. Serum levels of these phosphaturic hormones increase along with the progression of CKD, leading to extremely high concentrations in dialysis patients, which in turn causes hypophosphatemia after kidney transplantation. Recently, besides phosphorus levels, increase in FGF-23 levels has been shown to predict mortality and progression of CKD. Further studies should investigate whether management of phosphorus balance in early-stage CKD is helpful in improving clinical outcomes and whether FGF-23 can be used as a potential biomarker for monitoring the response to its management.