Abstract: 【Abstract】Objective To investigate the correlation between the serum levels of C-terminal fibroblast growth factor 23 (cFGF23) and intact fibroblast growth factor 23 (iFGF23) and the severity and progression of coronary artery calcification (CAC) in patients on maintenance hemodialysis (MHD). Methods The MHD patients treated in Beijing Anzhen Hospital during the last 5 years were enrolled as the research subjects. Their baseline data and laboratory examination results were collected. Serum cFGF23 and
iFGF23 were measured by ELISA. CAC score was estimated based on the CT scan image. Results A total of 37 patients were subjected to CAC examination. Patients in the severe CAC group had higher serum cFGF23 level than those in the non-severe CAC group [1128.6 (1073.2, 1252.8) RU/ml vs. 1036.9 (927.7, 1121.8) RU/ml, Z=-2.431, P=0.014], while serum iFGF23 level had no statistical difference between the two groups of patients (1892.4±951.8 pg/ml vs. 1506.8±1094.9 pg/ml, Z=-1.151, P=0.258). Logistic regression analysis revealed that serum cFGF23 level was independently correlated with the severity of CAC (OR=1.026, 95% CI 1.003~1.048, P=0.024), while serum iFGF23 level had no correlation with the severity of CAC (OR=0.999, 95% CI 0.998~ 1.001, P=0.466), after adjusting gender, age, dialysis vintage, iPTH, serum calcium and serum phosphorus of the patients. Twenty-six of the 37 patients completed the follow-up for 5 years. There were statistical differences in average iPTH within the 5 years [506.7 (166.8, 567.5) pg/ml vs. 684.6 (349.7, 1388.1) pg/ml, Z=-2.102, P=0.036], baseline CAC scores [45 (0, 142) vs. 317 (174, 964), Z=-2.943, P=0.003], serum cFGF23 at the end of follow-up [954.7 (891.3, 1073.2) RU/ml vs. 1128.6 (1093.9, 1252.8) RU/ml, Z=-3.192, P=0.001], CAC score at the end of follow-up [189 (106, 488) vs. 2228 (1159, 3104), Z=-3.971, P<0.001], and △cFGF23 [-55.4 (- 212.5, 71.1) RU/ml vs. 146.8 RU/ml (38.2, 399.7), Z=-2.31, P=0.021] between patients in rapid progress group and those in non-rapid progress group. Univariate correlation analysis found that △cFGF23 was positively correlated with CAC progression (r=0.399, P=0.043), and CAC progression rate was positively correlated with the occurrence of cardiovascular events (r=0.464, P=0.017). Conclusions Higher serum cFGF23 or rapid elevation of serum cFGF23 may indicate the MHD patient with severer or progressive CAC. In MHD patients, higher serum cFGF23 was independently correlated with the severity of CAC, △cFGF23 was positively correlated with the progression of CAC, while serum iFGF23 had no correlation with the severity and progression of CAC.

Key words: C-terminal fibroblast growth factor 23, Intact fibroblast growth factor 23, Coronary artery calcification, Hemodialysis