BACKGROUND: Fibroblast growth factor -23 (FGF-23) is a key regulator of mineral metabolism. It regulates renal phosphate (Pi) reabsorption and calcitriol synthesis, and has an inhibitory effect on parathyroid hormone (PTH) secretion. FGF-23 increases early in chronic kidney disease (CKD), but the regulation of FGF-23 in mild -to -moderate renal dysfunction is not fully understood. METHODS: Nine healthy kidney donors underwent unilateral nephrectomy. Estimated glomerular filtration rate (eGFR) calculated from cystatin C and parameters of mineral metabolism: (Pi, ionized calcium, biointact PTH, intact FGF-23, calcitriol, and urinary excretion of calcium and Pi) were analysed before surgery, and one day, one week and three to six months after surgery. RESULTS: On the first post-operative day, PTH increased due to a decrease in the calcium level. One week after nephrectomy, the FGF-23 level increased from 31.8 ± 12.3 pg/mL to 55.8 ± 15.1 pg/mL, while PTH, Pi and calcium levels were unchanged compared towith baseline. On follow-up, eGFR improved compared with its one-week value, and PTH and FGF-23 were unchanged compared towith baseline. The calcitriol level decreased but was in the normal range at all points in time. The total amount of Pi in urine did not change, while the calcium excretion decreased significantly. CONCLUSIONS: Pi homeostasis after nephrectomy is maintained by PTH on the first day. When serum calcium is stabilized and food intake resumed, FGF-23 rises, possibly in response to the Pi- load in relation to GFR.
BACKGROUND:Fibroblast growth factor -23 (FGF-23) is a key regulator of mineral metabolism. It regulates renal phosphate (Pi) reabsorption and calcitriol synthesis, and has an inhibitory effect on parathyroid hormone (PTH) secretion. FGF-23 increases early in chronic kidney disease (CKD), but the regulation of FGF-23 in mild -to -moderate renal dysfunction is not fully understood. METHODS: Nine healthy kidney donors underwent unilateral nephrectomy. Estimated glomerular filtration rate (eGFR) calculated from cystatin C and parameters of mineral metabolism: (Pi, ionizedcalcium, biointact PTH, intact FGF-23, calcitriol, and urinary excretion of calcium and Pi) were analysed before surgery, and one day, one week and three to six months after surgery. RESULTS: On the first post-operative day, PTH increased due to a decrease in the calcium level. One week after nephrectomy, the FGF-23 level increased from 31.8 ± 12.3 pg/mL to 55.8 ± 15.1 pg/mL, while PTH, Pi and calcium levels were unchanged compared towith baseline. On follow-up, eGFR improved compared with its one-week value, and PTH and FGF-23 were unchanged compared towith baseline. The calcitriol level decreased but was in the normal range at all points in time. The total amount of Pi in urine did not change, while the calcium excretion decreased significantly. CONCLUSIONS: Pi homeostasis after nephrectomy is maintained by PTH on the first day. When serum calcium is stabilized and food intake resumed, FGF-23 rises, possibly in response to the Pi- load in relation to GFR.
Authors: Tamara Isakova; Huiliang Xie; Allison Barchi-Chung; Gabriela Vargas; Nicole Sowden; Jessica Houston; Patricia Wahl; Andrew Lundquist; Michael Epstein; Kelsey Smith; Gabriel Contreras; Luis Ortega; Oliver Lenz; Patricia Briones; Phyllis Egbert; T Alp Ikizler; Harald Jueppner; Myles Wolf Journal: Clin J Am Soc Nephrol Date: 2011-09-08 Impact factor: 8.237
Authors: Bertram L Kasiske; Teresa Anderson-Haag; Ajay K Israni; Roberto S Kalil; Paul L Kimmel; Edward S Kraus; Rajiv Kumar; Andrew A Posselt; Todd E Pesavento; Hamid Rabb; Michael W Steffes; Jon J Snyder; Matthew R Weir Journal: Am J Kidney Dis Date: 2015-03-17 Impact factor: 8.860
Authors: Bertram L Kasiske; Teresa Anderson-Haag; Hassan N Ibrahim; Todd E Pesavento; Matthew R Weir; Joseph M Nogueira; Fernando G Cosio; Edward S Kraus; Hamid H Rabb; Roberto S Kalil; Andrew A Posselt; Paul L Kimmel; Michael W Steffes Journal: Am J Kidney Dis Date: 2013-03-22 Impact factor: 8.860
Authors: Bertram L Kasiske; Rajiv Kumar; Paul L Kimmel; Todd E Pesavento; Roberto S Kalil; Edward S Kraus; Hamid Rabb; Andrew M Posselt; Teresa L Anderson-Haag; Michael W Steffes; Ajay K Israni; Jon J Snyder; Ravinder J Singh; Matthew R Weir Journal: Kidney Int Date: 2016-06-28 Impact factor: 10.612