Introduction: Several studies showed the association of high levels of fibroblast growth factor 23 and parathormone with increased risk of bone disease in chronic kidney disease (CKD). Objectives: We conducted this study to determine the level of fibroblast growth factor 23 (FGF23) and parathormone in stages I and V of CKD.
Patients and Methods: In this cross-sectional study, three groups of children, consisted of 24 children with early stage of CKD, 40 with late stage of CKD (stage V; end-stage renal disease [EDRD] patients) and 21 healthy children enrolled to the study. Patient selection was based on random sampling method. Serum calcium, phosphate, intact parathyroid hormone (iPTH), FGF23 and serum creatinine levels and also glomerular filtration rate (GFR) were measured using standard assays.
Results: This study showed a significantly higher parathyroid hormone (PTH) level in the EDRD hemodialysis group in comparison with the early stage of CKD and control groups (P<0.001). Likewise, a significant difference of phosphorus between the EDRD hemodialysis group with the normal group and the early stage of CKD was detected. (P<0.001). A significant positive correlation of serum phosphorus with serum levels of FGF 23 in the EDRD patients (P<0.05) was seen, while this association in the early stage of CKD was absent (P>0.05). According to the results of the receiver operating characteristic (ROC) curve, serum FGF23 was not an appropriate prognostic index for GFR in pediatric patients with CKD (P=0.07) (sensitivity 40.8, specificity 83.3, cutoff point 134. 72). Meanwhile, the top of ROC curve shows, iPTH had acceptable sensitivity and specificity for determining different stages of CKD (P<0.0001, sensitivity= 100, specificity=97.2, cutoff point = 100.7).
Conclusion: FGF23 is not an appropriate prognostic tool in pediatric patients with early stage of CKD, however, iPTH had an acceptable sensitivity and specificity to determine various stages of CKD.