U‐shaped relationship between uric acid and residual renal function decline in continuous ambulatory peritoneal dialysis patients
Residual renal function (RRF) has been implicated to be important in maintaining fluid balance, phosphorus control, nutrition, and removal of both small‐ and middle‐sized solutes.8 More importantly, RRF has also been shown to be a crucial predictor of mortality, especially in peritoneal dialysis (PD) patents.9 And beyond survival benefits, RRF has been shown to have beneficial effects on anaemia, blood pressure control, hypervolaemia, left ventricular hypertrophy, bone metabolism and nutrition.11
There are many similarities between factors affecting the rate of decline in RRF in dialysis and those affecting the rate of GFR decline in CKD. However, to our knowledge, there is little information on the clinical impact of serum UA levels on the RRF of PD patients. Park et al. investigated the relationship by dividing subjects into either hyperuricaemia (UA ≧0.413 mmol/L) or normouricaemia (UA < 0.413 mmol/L),17 and some studies have reported a J‐shaped association between UA and all‐cause mortality in patients with kidney disease.2 The aim of this study, therefore, was to determine whether there is a J‐shaped relationship between baseline UA levels and RRF decline, as well as to determine the risk factors for anuria.