Abstract: 【Abstract】Objective To explore the relationship between the levels of urinary microRNA-34a (miR-34a) and serum uric acid (UA) and the renal function and prognosis in end stage renal disease (ESRD) patients undergoing continuous ambulatory peritoneal dialysis (CAPD) treatment. Methods A total of 200 cases of ESRD patients undergoing CAPD from January 2016 to October 2017 were assigned as the observation group and they were subdivided into mild, moderate and severe subgroups; a total of 100 volunteers were recruited as the control group. Urinary miR- 34a, serum uric acid, blood urea nitrogen and serum creatinine
(SCr) were measured, and eGFR was calculated. The weekly urea clearance index (Kt/V) and weekly creatinine clearance rate (CCR) after CAPD for one month were recorded, and residual renal function (RRF) was calculated. The effects of urinary miR-34a and serum UA on prognosis were then explored. Results ①Hemoglobin and serum albumin were significantly higher in the control group than in the observation group (F=94.867 and 44.315 respectively; P＜0.001), and serum phosphorus was significantly lower in the control group than in the observation group (F=17.589, P＜0.001). Hemoglobin and serum albumin were significantly
decreased and serum phosphorus was significantly increased along with aggravation of the disease (P＜0.05). ②eGFR, Kt/V, CCR and RRF decreased (F=9573.09, 27.499, 240.636 and 1095.17 respectively; P＜0.001), and BUN and SCr increased (F=721.543 and 2170.64 respectively; P＜0.001) along with aggravation of the disease. ③Urinary miR-34a and serum UA were significantly higher in the observation group than in the control group (χ2=49.352 and 341.151 respectively，P＜0.001), and were increased along with aggravation of the disease. ④Urinary miR-34a and serum UA were negatively correlated with eGFR, Kt/V, CCR and RRF (For miR-34a: r=-0.193, -0.147, -0.192 and -0.178 respectively; P=0.001, 0.038, 0.007 and 0.012 respectively. For UA: r=-0.175, -0.201, -0.183 and -0.254 respectively; P=0.002, 0.004, 0.010 and ＜0.001 respectively). Urinary miR-34a and serum UA were positively correlated with BUN and SCr (For miR-34a: r=0.125 and 0.160 respectively; P=0.030 and 0.006 respectively. For UA: r=0.121 and 0.149 respectively; P=0.036 and 0.009 respectively). ⑤The 3-year survival curve was statistically different between patients with higher levels of urinary miR-34a and serum UA and those with lower levels of urinary miR-34a and serum UA (χ2= 4.647 and 9.775 respectively; P=0.031 and 0.002 respectively). Conclusion Urinary miR-34a and serum UA were significantly
correlated with renal function and RRF. Higher levels of urinary miR-34a and serum UA suggest the unfavorable prognosis in ESRD patients with CAPD.

Key words: MicroRNA, Uric acid, Continuous ambulatory peritoneal dialysis, End-stage renal disease, Prognosis