Circulating FGF21 Levels Are Progressively Increased from the Early to End Stages of Chronic Kidney Diseases and Are Associated with Renal Function in Chinese

Background: Fibroblast growth factor 21 (FGF21) is a hepatic hormone involved in the regulation of lipid and carbohydrate metabolism. This study aims to test the hypothesis that elevated FGF21 concentrations are associated with the change of renal function and the presence of left ventricular hypertrophy (LVH) in the different stages of chronic kidney disease (CKD) progression. Methodology/Principal Findings: 240 subjects including 200 CKD patients (146 outpatients and 54 long-term hemodialytic patients) and 40 healthy control subjects were recruited. All CKD subjects underwent echocardiograms to assess left ventricular mass index. Plasma FGF21 levels and other clinical and biochemical parameters in all subjects were obtained based on standard clinical examination methods. Plasma FGF21 levels were significantly increased with the development of CKD from early-and end-stage (P < 0.001 for trend), and significantly higher in CKD subjects than those in healthy subjects (P < 0.001). Plasma FGF21 levels in CKD patients with LVH were higher than those in patients without LVH (P=0.001). Furthermore, plasma FGF21 level correlated positively with creatinine, blood urea nitrogen (BUN), beta 2 microglobulin, systolic pressure, adiponectin, phosphate, proteinuria, CRP and triglyceride, but negatively with creatinine clearance rate (CCR), estimated glomerular filtrate rate (eGFR), HDL-c, LDL-c, albumin and LVH after adjusting for BMI, gender, age and the presence of diabetes mellitus. Multiple stepwise regression analyses indicated that FGF21 was independently associated with BUN, Phosphate, LVMI and beta 2 microglobulin (all P < 0.05). Conclusion: Plasma FGF21 levels are significantly increased with the development of early-to end-stage CKD and are independently associated with renal function and adverse lipid profiles in Chinese population. Understanding whether increased FGF21 is associated with myocardial hypertrophy in CKD requires further study.