Evaluation of serum FGF23 in patients with beta-thalassemia major compared to healthy population and its associated factors

Background: The role of phosphate hemostasis in development of thalassemia bone disease has not been extensively studied yet. Due to the lack of sufficient human studies about the changes of serum Fibroblast growth factor-23(FGF23) in patients with beta-thalassemia major as the first step of investigating the role of FGF23 in thalassemia bone disease, the present study aimed to investigate the serum level of FGF23 in patients with thalassemia major. Material and Method: In this case-control study, 25 patients with beta thalassemia major and their age- and sex-matched healthy volunteers were enrolled. Serum phosphorous, calcium, parathyroid hormone (PTH), 25(OH) D, erythropoietin (EPO), serum intact FGF23 (iFGF23) and 1,25 (OH)2 D were checked and analyzed. Result: Patients with beta-thalassemia major had lower 1,25 (OH)2D, (p = 0.025), higher phosphate (p = 0.002), and higher PTH (P <0.001) compared to the control group; however, all of them were in their normal blood range. They also had higher serum FGF23 (p = 0.007) and higher EPO (P<0.001). Serum FGF23 had an independent association with serum Iron (p=0.016), 1, 25(OH)2 Vitamin D (p<0.001), and hemoglobin (p=0.002). Conclusion: Serum FGF23 was associated with serum Iron, 1, 25(OH)2 Vitamin D, and hemoglobin in beta-thalassemia major patients. Hence, it seems that regular transfusions and chelating agents which can decrease the serum iron and increase hemoglobin level can be associated with lower iFGF23.