title: Rate of decline of residual renal function is associated with all-cause mortality and technique failure in patients on long-term peritoneal dialysis.
abstract: BACKGROUND
  Residual renal function (RRF) at the initiation of peritoneal dialysis (PD) therapy can predict patient outcome. However, RRF declines with time at variable rates in different patients. This study was performed to compare the impact of baseline RRF and the rate of RRF decline on patient survival and on death-censored technique survival after initiation of long-term PD.
  
  
  METHODS
  We enrolled 270 patients with sufficient urine amount (daily urine volume >100 mL) from a medical centre in North Taiwan who began PD between January 1996 and December 2005 and followed them until December 2007. The study population was stratified by the decline rate of RRF into a fast, intermediate and slow decline group. The Kaplan-Meier survival analysis was used to determine patient survival and technique survival. The Cox regression model was used to identify factors associated with patient outcome. The proportional odds polychotomous logistic regression model was used to identify variables associated with rapid decline of RRF.
  
  
  RESULTS
  During an average follow-up period of 45 months, 50 (18.5%) deaths, 67 (24.8%) death-censored technique failures (transfer to haemodialysis) and 43 (15.9%) renal transplantations occurred. The median rate of RRF decline was 0.885 mL/min/1.73 m(2) per year. Survival analysis showed that patients with fast RRF decline had worse survival and increased risk of technique failure. The multivariate Cox regression model confirmed that the rate of RRF decline was an independent factor associated with patient and technique survival and was a more powerful prognostic factor than basal RRF. Variables associated with a rapid decline of RRF were larger body mass index, presence of diabetes, prior history of congestive heart failure, use of diuretics, peritonitis episodes and hypotensive events.
  
  
  CONCLUSIONS
  Our data indicate that the rate of decline of RRF is a more powerful prognostic factor than baseline RRF associated with all-cause mortality and technique failure in patients on long-term PD. To prevent accelerated loss of RRF, it is imperative that every effort be made to avoid overdiuresis, peritonitis and hypotensive episodes, especially in those with diabetes, obesity and congestive heart failure.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chia-Te
authors.initials: CT
authors.lastname: Liao
authors.forename: Yung-Ming
authors.initials: YM
authors.lastname: Chen
authors.forename: Chih-Chung
authors.initials: CC
authors.lastname: Shiao
authors.forename: Fu-Chang
authors.initials: FC
authors.lastname: Hu
authors.forename: Jenq-Wen
authors.initials: JW
authors.lastname: Huang
authors.forename: Tze-Wah
authors.initials: TW
authors.lastname: Kao
authors.forename: Hsueh-Fang
authors.initials: HF
authors.lastname: Chuang
authors.forename: Kuan-Yu
authors.initials: KY
authors.lastname: Hung
authors.forename: Kwan-Dun
authors.initials: KD
authors.lastname: Wu
authors.forename: Tun-Jun
authors.initials: TJ
authors.lastname: Tsai
mesh_terms: D000328:Adult; D000368:Aged; D015897:Comorbidity; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000503:physiopathology*; D007676:Kidney Failure, Chronic / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000009:adverse effects / Q000401:mortality; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors