Abstract: Objective  To explore serum levels of fibroblast growth factor-23 (FGF-23) and soluble growth stimulation expressed gene 2 (sST2) in the prediction of heart valve calcification in elderly patients with end-stage renal disease (ESRD) on hemodialysis.  Methods  A total of 106 elderly ESRD patients on hemodialysis admitted to the Seventh Affiliated Hospital of Xinjiang Medical University from June 2018 to June 2021 were recruited as the observation group, and a total of 106 healthy individuals for physical check-up were recruited as the control group. Serum FGF-23 and sST2 levels were compared between the two groups. The observation group was followed up until January 2022, and the incidence of heart valve calcification in this group was then calculated. The influencing factors for heart valve calcification and the interaction of FGF-23 and sST2 in the pathogenesis of heart valve calcification were analyzed. The values of FGF-23 and sST2 in predicting heart valve calcification were then evaluated.  Results Serum FGF-23 and sST2 levels were higher in the observation group than in the control group (t=35.539 and 45.748, P＜0.001). Higher expressions of FGF-23 and sST2 increased the risk of heart valve calcification (OR=4.539 and 4.265, 95% CI：2.527~8.154 and 2.008~9.057, P＜0.001). After adjusting for confounding factors, there was a positive interaction between FGF-23 and sST2 on the occurrence of cardiac valve calcification. The synergistic effect was 2.631 times higher than the sum of the effects of the two individually (SI=2.631). The area under the curve (AUC) of combined FGF-23 and sST2 was greater than that of FGF-23 or sST2 for the prediction of heart valve calcification (AUC=0.851, 95% CI：0.767~0.913, P＜0.001).   Conclusion  Serum FGF-23 and sST2 levels abnormally increased in elderly ESRD patients on hemodialysis. The effects of FGF-23 and sST2 were synergistic in the pathogenesis of heart valve calcification, and combination of the two can efficiently improve the prediction of heart valve calcification.

Key words: Elderly, End stage renal disease, Hemodialysis, Fibroblast growth factor 23, Soluble growth-stimulating gene 2 protein, Heart valve calcification