Purpose: To investigate the correlation of serum fibroblast growth factor-23 (FGF-23) with urinary fractional excretion of phosphate (FEPi) in predialysis chronic kidney disease (CKD).
Methods: This cross-sectional study involved 75 patients with CKD stage 2-4. Blood and 24-hour urine samples were taken from eligible participants to measure key variables using standard commercial assays. FGF-23 concentration was measured using enzyme-linked immunosorbent assay (ELISA). The correlation between FGF-23 serum level and urinary FEPi was analyzed using the Spearman correlation test.
Results: Of 75 eligible subjects, the majority had the characteristics of male gender, CKD stage 3, with mean age and body mass index of 50Â±10.8 and 23.51Â±3.3, respectively. The median FGF-23 level was 108.7 (13.6-1226.2) RU/ml, while the median urinary FEPi was 24.3% (4.04%-65.9%). There was a moderate positive correlation between FGF-23 and FEPi (r = 0.44, p<0.001).
Conclusion: The result confirmed the correlation between serum FGF-23 level with urinary FEPi in predialysis CKD.