OBJECTIVES: It is unclear whether fibroblast growth factor-23 (FGF-23) increases in response to phosphate accumulation or to decrease clearance in chronic kidney disease (CKD) as is the case with other low molecular weight proteins such as cystatin C (CysC). DESIGN AND METHODS: This cross-sectional study measured serum FGF-23, CysC, and other serum markers of bone metabolism in 69 patients, aged 18 months-24 years, with various stages of CKD (eGFR=11-214mL/min). RESULTS: FGF-23 levels were significantly correlated with CysC and parathyroid hormone levels (PTH) on univariate non-linear regression analysis. In multivariate linear regression analysis, log (CysC) (β=0.660, p<0.0001), log (PTH) (β=0.038, p=0.37), and phosphate (β=0.222, p=0.028) explained 69.1% of the variance of FGF-23. CONCLUSIONS: CysC had the largest unique contribution to FGF-23 variance in this model, supporting the hypothesis that renal clearance may be the most responsible factor for elevated FGF-23 levels in early stages of CKD.
OBJECTIVES: It is unclear whether fibroblast growth factor-23 (FGF-23) increases in response to phosphate accumulation or to decrease clearance in chronic kidney disease (CKD) as is the case with other low molecular weight proteins such as cystatin C (CysC). DESIGN AND METHODS: This cross-sectional study measured serum FGF-23, CysC, and other serum markers of bone metabolism in 69 patients, aged 18 months-24 years, with various stages of CKD (eGFR=11-214mL/min). RESULTS:FGF-23 levels were significantly correlated with CysC and parathyroid hormone levels (PTH) on univariate non-linear regression analysis. In multivariate linear regression analysis, log (CysC) (β=0.660, p<0.0001), log (PTH) (β=0.038, p=0.37), and phosphate (β=0.222, p=0.028) explained 69.1% of the variance of FGF-23. CONCLUSIONS:CysC had the largest unique contribution to FGF-23 variance in this model, supporting the hypothesis that renal clearance may be the most responsible factor for elevated FGF-23 levels in early stages of CKD.
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: Marta Christov; Sushrut S Waikar; Renata C Pereira; Andrea Havasi; David E Leaf; David Goltzman; Paola D Pajevic; Myles Wolf; Harald Jüppner Journal: Kidney Int Date: 2013-05-08 Impact factor: 10.612