Abstract:  Objective: To  investigate  the  relationship  between  the  rate  of  urine  volume  decline  and  adverse outcomes in peritoneal dialysis (PD) patients.    Methodology:This study enrolled PD patients who received regular follow⁃ ups at the Peritoneal Dialysis Center, Department of Nephrology, First Affiliated Hospital of Wenzhou Medical University, between March 1996 and December 2022. Demographic data and laboratory parameters were collected, and the rate of urine output decline was calculated. The  association  between  the  rate  of  urine  output  volume  and  adverse  outcomes  (all⁃cause mortality and permanent  transition  to  hemodialysis)  was  further  analyzed.     Results: A  total  of  1, 090  PD  patients  were included, of whom 622 (57.1%) were male. The mean age at the initiation of PD was 49.12±13.33 years, with a baseline urine volume of 960.28±436.80 mL. The median follow⁃up duration was 55.05±40.04 months. Adverse outcomes occurred in 317 patients (29.9%), including 115 deaths (10.6%) and 202 permanent transitions to hemodialysis (18.5%). Based on the logarithmic values of urine  volume  decline  rates  (absolute  slope  values),  patients  were  divided  into  four  groups: rapid decline group [ Q1:(2.80,  4.48)],  moderate⁃rapid  decline  group  [ Q2:(2.08,  2.80)],  moderate⁃slow  decline group [ Q3:(1.42, 2.08)], and slow decline  group  [ Q4:(0.05, 1.42)].  Significant  differences  were  observed  among the  four groups in terms of gender, age, adverse outcome rates, follow⁃up duration, residual urine volume, serum albumin, hemoglobin, blood urea  nitrogen,  and  parathyroid  hormone  levels  (P< 0.05).  Kaplan⁃Meier  survival  analysis  revealed  a significant  association  between  the  rate  of  urine  volume  decline  and  adverse  outcomes  (log⁃rank  test,  P < 0.001 ). Multivariate  Cox  regression  analysis,  after  adjusting  for  confounding  factors  such  as  age,  systolic  blood  pressure,  serum albumin, and  total  cholesterol,  identified  the  rate  of  urine  volume  decline  as  an  independent  risk  factor  for  adverse outcomes in PD patients. For every unit increase in the rate of urine volume decline, the risk of adverse outcomes increased by 3.77 times  (Model  2:  P < 0.001).     Conclusion: The  rate  of  urine  output  decline  is  an  independent  risk  factor  for adverse outcomes in PD patients.  Strengthening  individualized management  and preserving  residual  urine  output  may  help improve the prognosis of PD patients.

Key words: peritoneal dialysis   , urine volume   , residual renal function   , poor prognosis