Relationship between cFGF23/Klotho ratio and phosphate levels in patients with chronic kidney disease
To characterize the relationship between the cFGF23/Klotho ratio and phosphate level in patients with chronic kidney disease (CKD).
A total of 152 patients with CKD stage 3–5 (CKD stage 3: n = 74; CKD stage 4: n = 60; CKD stage 5: n = 18) were included in the study. Thirty healthy volunteers served as controls. Intact-FGF23, cFGF23, Klotho, serum calcium, serum phosphate, and serum creatinine were measured, and estimated glomerular filtration rate (eGFR) was calculated. The Kruskal–Wallis H test was used for comparison between groups, and the Spearman test was used for correlation analysis.
In CKD stage 3–5, creatinine and iFGF23 levels, as well as the cFGF23/Klotho ratio, were higher (P < 0.01), phosphate levels were higher (P < 0.05), and Klotho levels were lower (P < 0.01), compared with controls. C-terminal-FGF23 levels were higher in CKD phase 4–5 (P < 0.05). In CKD stage 4–5, creatinine, iFGF23, and phosphate levels, as well as the cFGF23/Klotho ratio, were higher (P < 0.01), cFGF23 levels were higher (P < 0.05), and Klotho levels were lower (P < 0.05), compared with CKD stage 3. In CKD stage 5, creatinine and cFGF23 levels, as well as the cFGF23/Klotho ratio, were higher (P < 0.01), phosphate and iFGF23 levels were higher (P < 0.05), and Klotho levels were lower (P < 0.01), compared with CKD stage 4. Phosphate was positively correlated with the cFGF23/Klotho ratio (r = 0.235, P < 0.01).
EGFR reduction was associated with an increased cFGF23/Klotho ratio, and the cFGF23/Klotho ratio was positively correlated with phosphate. This suggests that the phosphate level can be controlled by modifying the cFGF23/Klotho ratio.
KeywordsCKD Serum phosphate Klotho iFGF23–Klotho signaling axis cFGF23/Klotho ratio
We thank S. Win, PhD, and Ryan Chastain-Gross, PhD, from Liwen Bianji, Edanz Editing China (http://www.liwenbianji.cn/ac) for editing a draft of this manuscript.
This study was supported by the Chinese Medicine Science and Technology Project of Fujian Provincial Health Department (Grant no. WZSb201316).
Compliance with ethical standards
Conflict of interest
There are no conflicts of interest to declare.