Correlation Between Fibroblast Growth Factor 23 and Biochemical Parameters in Hemodialysis Patients With End-Stage Renal Disease.

Background: Fibroblast growth factor 23 (FGF-23) is one of the biomarkers that plays a role in regulating phosphate (P) levels in hemodialysis (HD) patients with end-stage renal disease (ESRD). In addition to FGF-23, intact parathyroid hormone (iPTH) and homocysteine (Hcy) also play a role in the chronic kidney disease (CKD)-related mineral bone disease (MBD) process. In this study, we evaluated the correlation of glomerular filtration rate (GFR), serum creatinine, calcium, and phosphorus levels with FGF-23, iPTH, and Hcy. These parameter values may guide us for new prognostic and treatment definition targets in HD patients with ESRD.

Methods: We retrospectively evaluated serum FGF-23, Hcy, and iPTH concentrations in 103 HD patients with ESRD. Biochemical laboratory parameter data were analyzed to determine the correlation between GFR, blood creatinine, phosphorus, and calcium levels. The inclusion criteria for this study were patients with chronic kidney disease who were undergoing HD and did not have primary cardiovascular disorders. The exclusion criteria included patients with primary cardiovascular disease undergoing HD; patients with acute renal failure; patients with acute cardiovascular failure, and patients with other pathologies undergoing HD (e.g. autoimmune and oncological diseases, patients who had undergone surgery within the last two months). Color Doppler Echocardiography and Electrocardiogram (ECG) were performed to all HD patients for cardiac evaluation. Before HD blood samples were collected and the centrifugation method was used for serum fluid collection. We used the ELISA method to record demographic data and biochemical laboratory parameter results for all patients.

Results:  In 103 cases of HD patients, 65 were male (63.1%) and 38 were female (36.9%). The mean ± SD parameter result for age was 64±13.64. The detailed baseline information for biochemical laboratory parameters, including Hg, CRP, glucose, creatinine, GFR, K, Na, Ca, P, ALT, AST, iPTH, Hcy, and FGF-23, were evaluated. FGF-23 levels were positively correlated with serum P (r=0.78, p=0.01), iPTH (r=0.61, p=0.01), and creatinine (r=0.78, p=0.01) and negatively with GFR (r=-0.64, p=0.01). FGF-23 and Hcy showed a positive linear correlation (r=0.65, p=0.01). No statistically significant correlation was found with Ca values (r=-0.12, p>0.05).  Conclusion: There is no single biomarker that can completely predict CKD progression and follow-up. Changes in FGF-23, iPTH, and Hcy levels together and correlation with other biochemical laboratory parameters may be the earliest markers for HD patients. These parameter values together can be used to guide strategies for the prognostic issues and early treatment management.