Relation Between Fibroblast Growth Factor-23 and Red Cell Distribution Width in Patients with End-Stage Renal Disease Undergoing Hemodialysis

Introduction. Fibroblast growth factor-23 (FGF23) is responsible for regulating the metabolism of phosphorus and vitamin D by affecting the kidneys and parathyroid gland. Phosphate is present in the 2, 3-diphosphoglycerate (2,3DPG) ester composition, which can shift the O2-Hb dissociation curve to the right. Therefore, we hypothesized that maybe there is an association between red cell distribution width (RDW) and FGF23 level. The aim of this study was to investigate the relationship between iFGF23 and RDW in patients with end-stage renal disease undergoing hemodialysis. Methods. This cross-sectional study was performed on 254 endstage renal diseases (ESRD) patients undergoing hemodialysis who were admitted to Rasht Razi Hospital Hemodialysis Center, in 2017. We used Shapiro-Wilk, Spearman correlation coefficient, Mann– Whitney U-test, and Multiple Linear Regression Analysis. All statistical analyses were performed by SPSS software. Results. The median age of patients was 60 years (IQR: 49 to 69). The mean and median iFGF23 concentration in patients were 59.5 ± 14.6 and 62 (IQR: 49 to 69) pg/mL, respectively. According to spearman test, iFGF23 had a statistically significant association with age (r = 0.856, P < 0.001), MCV (r = 0.202, P < .001), phosphorus (r = -0.176, P < .05), weight difference before and after dialysis (r = -0.264, P < .05), and Vitamin D (r = -0.201, P < .05). Also in multiple linear regression analysis, the variables of RDW, IDWG, iPTH, MCH, DM, HTN, Age, and CRP were considered as predictors of iFGF23 . Conclusion. RDW was identified as one of the predictors of iFGF23 changes. Perhaps in the future, more value will be given to the role of RDW in dialysis patients.