Uric acid is associated with the rate of residual renal function decline in peritoneal dialysis patients

Background. Uric acid (UA) is known to play a pathogenic role in chronic kidney disease (CKD). However, its effect in end-stage renal disease (ESRD) has not yet been elucidated. We explored the prevalence of hyperuricaemia and the relationship between UA and residual renal function (RRF) in peritoneal dialysis (PD) patients. Methods. The subjects of this study were 134 PD patients who started dialysis at the Yonsei University Health System between January 2000 and December 2005. Timed urine collections were performed within I month of PD commencement and at 6-month intervals thereafter. The slope of decline of RRF over time was calculated by linear regression analysis of serial urinary urea and creatinine clearances for each patient. Biochemical and clinical data at the time of initial urine collection were considered as baseline. Results. At baseline, 32.8% of the PD patients had hyperuricaemia (UA >= 7.0 mg/dl). A significant majority of patients with hyperuricaemia were diabetic (P = 0.02). Hypertensive patients had a higher UA level (P = 0.002) compared to normotensive patients. The overall reduction rate of RRF in hyperuricaemic patients was significantly higher than in the normouricaemic group (P = 0.001). In the multiple linear regression analysis, hyperuricaemia and history of DM showed a significant negative correlation with the reduction rate of RRF after adjusting for demographic data, comorbid conditions, body mass index, baseline RRF and medications (P = 0.001). Conclusions. Hyperuricaemia is common among PD patients and is significantly associated with the rate of decline of RRF.