Elevated serum fatty acid-binding protein 4 level predicts all-cause and cardiovascular mortality in peritoneal dialysis patients: a five-year study

BACKGROUND: To explore the prospective role of serum fatty acid-binding protein 4 (FABP4) in the outcomes of peritoneal dialysis (PD) patients. METHODS: A prospective observational study was conducted with 159 patients on PD. Demographic and clinical data at baseline were collected from medical records. Biochemical data were recorded based on blood samples measured in a central laboratory. Serum FABP4 concentrations were determined using enzyme-linked immunosorbent assay. Body composition was measured using a Body Composition Monitor. Abdominal lateral plain radiography was used to evaluate vascular calcification. The primary endpoints were all-cause and cardiovascular death. RESULTS: The median of serum FABP4 concentration was 154.6 ng/mL (interquartile range, 132.8–269.7 ng/mL). Increased serum FABP4 was associated with increased vascular calcification proportion, time on dialysis, body mass index, high-sensitivity C-reactive protein (hs-CRP), intact parathyroid hormone (iPTH), triglycerides, body fat mass, and body fat percentage (p < 0.05). Increased serum FABP4 was associated with decreased residual kidney Kt/V urea (p < 0.05). Patients with hs-CRP≥ 3 mg/L had significantly higher serum FABP4 than those with hs-CRP< 3 mg/L (p < 0.05). Patients with vascular calcification had significantly higher serum FABP4 than those without vascular calcification (p < 0.05). During a median follow-up of 58.0 months, 58 all-cause deaths and 26 cardiovascular deaths occurred. High serum FABP4 levels were independently predictive for all-cause [hazard ratio (HR), 1.003; 95% confidence interval (CI), 1.001–1.005; p = 0.016] and cardiovascular death (HR, 1.005; 95% CI, 1.001–1.008; p = 0.006) in PD patients. CONCLUSIONS: Increased serum FABP4 levels can independently predict all-cause and cardiovascular death in patients on PD.