Effects of serum uric acid level on all-cause death and cardiovascular death in patients of maintaining peritoneal dialysis

Objective To investigate the effects of serum uric acid (SUA) on all-cause death and cardiovascular death in patients of maintaining peritoneal dialysis (PD). Methods One thousand and sixty-three PD patients in the First Affiliated Hospital of Zhejiang University Medical College were included. The SUA levels at 6 months after PD start were measured. Patients with SUA≥420 μmol/L were grouped in hyperuricemia group (492 cases) and patients with SUA＜420 μmol/L were grouped in normal uric acid group (571 cases). The effects on all-cause mortality and cardiovascular mortality were retrospectively analyzed. Results The median age of the patients was 51(41, 62) years; 557 cases were male (52.40%); the median follow-up time was 33(20, 54) months (6-96 months); 167 cases (15.71%) died during the follow-up period, including 64 cases (6.02%) with cardiovascular causes. The mortality in hyperuricemia group was 19.11%(94/492) and the cardiovascular mortality was 7.93%(39/492), both rates were higher than those in normal uric acid group, and the differences were statistically significant (P=0.005, P=0.015, respectively). Hyperuricemia (SUA≥420 μmol/L) at 6 months after PD start (HR=1.572, 95%CI 1.155-2.141, P=0.004), high uric acid level (continuous variable) at 6 months after PD start (HR=1.002, 95%CI 1.001-1.004, P=0.008), and age≥65 years (HR=3.571, 95%CI 2.556-4.990, P＜0.001), serum albumin≤30 g/L (HR=1.907, 95%CI 1.278-2.845, P=0.002), high Charlson comorbidity index (HR=1.209, 95%CI 1.032-1.417, P=0.019) at the beginning of PD start were independent risk factors for all-causes death in PD patients. Hyperuricemia (SUA≥420 μmol/L) at 6 months after PD start (HR=1.734, 95%CI 1.033-2.912, P=0.037) and age≥65 years (HR=1.761, 95%CI 1.024-3.209, P=0.041), with diabetes (HR=2.775, 95%CI 1.358-5.671, P=0.005) at the beginning of PD start were independent risk factors for cardiovascular death in PD patients. Conclusions SUA at 6 months after PD is an independent risk factor for all-cause death and cardiovascular death in PD patients.