To analyze the influencing factors of serum fibroblast growth factor 23 (FGF23) level in maintenance hemodialysis (MHD) patients, and to explore its relationship with mineral bone metabolism disorders and vascular calcification.

From January to February of 2018, a total of 380 patients who had undergone MHD for more than 3 months in our hospital were enrolled for this study. Clinical parameters were recorded, including gender, age, dialysis age, dialysis adequacy, and use of phosphorus-reducing drugs. Before dialysis, blood was drawn for detection of serum calcium, phosphorus, intact parathyroid hormone (iPTH), and alkaline phosphatase as mineral bone metabolism indicators, as well as hemoglobin, albumin, blood glucose, blood lipids, high-sensitivity C-reactive protein (hs-CRP), and β2 microglobulin, etc. The serum level of FGF23 was determined with enzyme-linked immunosorbent assay (ELISA), while multislice spiral CT (MSCT) was used to evaluate coronary artery calcification scores. The t-test and chi-square test were applied to analyze the influencing factors of FGF23 in the MHD patients. Multivariate linear regression analysis was performed for multivariate analysis. The chi-square test was also used to analyze the correlation between parathyroid hormone and coronary artery calcification scores in the MHD patients with different FGF23 levels.

The median level of serum FGF23 in the MHD was 8 905.3 pg/ml. According to 50% of the FGF23 median level, the patients were divided into high-level group and low-level group. Univariate analysis showed that dialysis age, dialysis duration, dialysis ultrafiltration volume, and dialysis frequency were the influencing factors of serum FGF23 level. The level of FGF23 was higher in patients with larger age, longer duration of dialysis, more frequent dialysis, and greater volume of dialysis ultrafiltration (P<0.05). In the FGF23 high-level group, blood urea nitrogen, serum creatinine, and serum β2 microglobulin levels were higher than in the FGF23 low-level group (P<0.05). Multivariate linear regression analysis showed that dialysis age and serum creatinine were risk factors for the increase of FGF23 (P<0.001). And high FGF23 level was associated with the levels of serum calcium, serum phosphorus, iPTH, and high coronary artery calcification scores.

Dialysis age, dialysis duration, dialysis ultrafiltration volume, dialysis frequency, blood urea nitrogen, serum creatinine, serum β2 microglobulin, were related to the maintenance of FGF23 elevation in MHD patients. Dialysis AGE and serum creatinine were risk factors for FGF23 elevation. FGF23 was significantly associated with mineral-bone metabolism and coronary artery calcification in MHD patients.