Correlations of FGF23 and Klotho with cardiovascular injury in chronic kidney disease patients

Abstract

To analyze the levels of serum calcium, phosphate, fibroblast growth factor 23 (FGF23), and Klotho proteins in patients with chronic kidney disease (CKD), and to investigate the correlations of FGF23 and Klotho proteins with cardiac complicates in patients with chronic kidney disease-mineral and bone disorder (CKD-MBD). Methods: A total of 180 CKD-MBD patients were enrolled for this study. Among them, 60 patients underwent regular hemodialysis, 60 patients did not undergo renal replacement therapy and 60 patients were diagnosed as second hyperparathyroidism (SHPT). Thirty age and gender-matched health volunteers served as controls. Serum samples were collected and tested, and the demographical, clinical and biochemical data were all recorded. FGF23 and Klotho levels in serum samples were analyzed by enzyme-linked immunosorbent assay. Data of echocardiography and plain abdominal X rays were collected as well. The influential factors for cardiovascular injury, the relationship between biochemical indexes and ectopic calcification, and the correlations of FGF23 and Klotho with cardiac complicates were analyzed Results: Patients, who kept hemodialysis, especially those with SHPT, exhibited an increase in serum FGF23 level while a decrease in serum Klotho protein levels (P<0.01). Patients with higher levels of serum FGF23 were more likely to have ectopic calcification (OR=4.667), while patients with lower levels of serum Klotho had high risks to get myocardial hypertrophy (OR=3.496). Receiver operator characteristic (ROC) curve analysis showed that the area under the curve (AUC) for FGF23 was 0.778 (P<0.01) while for Klotho was 0.715 (P<0.01). Conclusion: Patients, who kept hemodialysis, especially those with SHPT, have a significant increase in serum FGF23 protein levels and a significant decrease in serum Klotho protein levels. Serum FGF23 and Klotho protein levels are closely correlated with left ventricular enlargement and hypertrophy. Serum FGF23 and Klotho protein are risk factors for heart.