Abstract: Objective To elucidate the relationship between fibroblast growth factor-23 (FGF23) and coronary artery calcification, and the prognostic value of FGF23 in chronic kidney disease (CKD) patients at moderate to advanced stage. Methods Serum intact FGF23 was measured by using ELISA in 150 CKD patients at stages 3-5. The relationship between FGF23 and coronary artery calcification was evaluated. Patients were followed up for 35±3 months, and the occurrence of cardiovascular disease (CVD) and death were recorded. Results Serum FGF23 level was significantly higher in CKD patients than in healthy controls (P＜0.01), and was much higher in dialyzed patients than non-dialyzed patients (P＜0.01), especially higher in hemodialysis patients. Serum FGF23 level was positively correlated with coronary artery calcification score (CaS) (r=0.177, P＜0.05). Logistic regression analysis showed that age, dialysis duration and FGF23 level were the independent risk factors for coronary artery calcification in CKD patients at moderate to advanced stage. During the follow-up, CVD in 21 (14%) patients and death in 13 (8.7%) patients were recorded. Patients were then stratified to two groups by the median FGF23 level (675.8pg/ml). Kaplan-Meier survival curves showed that patients with FGF23 levels ≥675.8pg/ml had significantly higher CVD incidence rate (P＜0.01) and all-cause mortality (P＜0.05) than those with FGF23 levels below the cut-off value. Cox regression analysis showed that FGF23 ≥675.8pg/ml and severe coronary artery calcification (CaS ＞400) were the independent risk factors for CVD in CKD patients, and that FGF23 level and severe coronary artery calcification (CaS ＞400) were the independent risk factors for all-cause mortality in CKD patients. Conclusion Serum FGF23 level in CKD patients at moderate to advanced stage was significantly higher than that in normal population. Serum FGF23 level may relate to coronary artery calcification and adverse clinical outcomes in CKD patients at moderate to advanced stage.

Key words: Fibroblast growth factor-23, Moderate to advanced stage chronic kidney diseases, Coronary artery calcification, Prognosis