High C-Terminal Fibroblast Growth Factor-23, Intact Parathyroid Hormone, and Interleukin-6 as Determinants of Valvular Calcification in Regular Hemodialysis Patients

Purpose: Biggest cause of death in chronic kidney disease-hemodialysis (CKD-HD) patients is cardiovascular disease (CVD). Cardiovascular disease is often associated with mineral bone disorders (MBD), especially vascular and valvular calcification. Biomarkers such as C-terminal-fibroblast growth factor-23 (FGF-23), intact parathyroid hormone (iPTH), and interleukin-6 (IL-6) were investigated. Only few studies have focused on valvular calcification in CKD-HD patients, with controversial results. The present study aimed to investigate whether high C-terminal-FGF-23, iPTH, and IL-6 can be used as determinants of valvular calcification in CKD-MBD patients undergoing regular HD. Patients and Methods: This was an analytical cross-sectional study which involved CKD-HD patients aged 18-60 years with no history of CVD, malignancy, and diabetes mellitus. C-terminal FGF-23 was measured using enzyme-linked immunosorbent assay (ELISA) kit, iPTH using chemiluminescent immunometric method, and IL-6 using sandwich enzyme immunoassay technique. Valvular calcification on aortic and mitral valves was examined with echocardiography. Data analysis was done using Chi-square d test or Fisher's exact test as appropriate and multivariate logistic regression analysis. Results: Bivariate analysis with Fisher's exact test showed significant association of prevalence ratio (PR) of C-terminal FGF-23 (PR = 1.33; p = 0.003; CI (1.017-1.748)), iPTH (PR = 1.361; p = 0.002; CI (1.02-1.816)), and IL-6 (PR = 1.2; p = 0.019; CI (1.000-1.446)) with valvular calcification. Multivariate analysis with logistic regression showed high C-terminal FGF-23 (exp (B) value of 16.44; p = 0.045; CI (1.07-252.75)), iPTH (exp (B) value of 33.312; p = 0.016; CI (1.94-571.71)), and IL-6 (exp (B) value of 21.58; p = 0.0381; CI (1.18-394.87)) were determinants of valvular calcification in CKD-MBD patients undergoing regular HD. Conclusion: This study demonstrated that high C-terminal FGF-23, iPTH, and IL-6 were determinants of valvular calcification in CKD-MBD patients undergoing regular HD.