[Kidney and bone update : the 5-year history and future of CKD-MBD. CKD-MBD and phosphotropic hormones].

During the progression of CKD, secondary hyperparathyroidism develops. It has been proposed that low 1,25-dihydroxyvitamin D, hyperphosphatemia and hypocalcemia contribute to the development of secondary hyperparathyroidism. Recent findings indicate that FGF23 begins to increase before the increment of parathyroid hormone. In addition, FGF23 seems to work to decrease 1,25-dihydroxyvitamin D while it also works to prevent the development of hyperphosphatemia by increasing urinary phosphate excretion together with PTH. However, it is not entirely clear what triggers the increase of FGF23 in patients with CKD.