title: Comparison of residual renal function in patients undergoing twice-weekly versus three-times-weekly haemodialysis.
abstract: OBJECTIVE
  Patients with end-stage renal disease (ESRD) often start long-term haemodialysis (HD) thrice weekly, regardless of the level of residual renal function (RRF). In this study, we investigated whether ESRD patients having sufficient RRF can be maintained on twice-weekly HD, and how they fare compared to patients without RRF on thrice-weekly HD.
  
  
  METHODS
  We analyzed 74 patients who had undergone long-term HD and maintained on the same dialysis frequency from February 1998 to July 2005, and followed until December 2005. We compared the clinical variables between twice-weekly and thrice-weekly HD patients and a second analysis testing the residual urine output as an independent predictor for twice-weekly HD.
  
  
  RESULTS
  After a mean follow up of 18 months, twice-weekly HD patients (n = 23) had lower serum beta2-microglobulin than thrice-weekly HD patients (n = 51). Moreover, the twice-weekly group had a slower decline of RRF, as indicated by their higher urine output and creatinine clearance, fewer intradialytic hypotensive episodes, and required less frequent hospitalization. There was no difference between the two groups in cardiothoracic ratio or indices of nutrition and inflammation. Multivariable logistic regression identified age (odds ratio (OR), 1.866; 95% CI, 1.093-3.183), dry body mass index (OR, 0.790; 95% CI, 0.625-0.999), and urine output (OR, 1.093; 95% CI, 1.026-1.164) as predictors for maintaining twice-weekly HD.
  
  
  CONCLUSIONS
  Our data suggest that when patients who have sufficient urine output are given twice-weekly HD, they maintain dialysis adequacy and exhibit better preservation of RRF than patients on thrice-weekly HD.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin and National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Lin
authors.forename: Jeng-Wen
authors.initials: JW
authors.lastname: Huang
authors.forename: Ming-Shiou
authors.initials: MS
authors.lastname: Wu
authors.forename: Tzong-Shinn
authors.initials: TS
authors.lastname: Chu
authors.forename: Shuei-Liong
authors.initials: SL
authors.lastname: Lin
authors.forename: Yung-Ming
authors.initials: YM
authors.lastname: Chen
authors.forename: Tun-Jun
authors.initials: TJ
authors.lastname: Tsai
authors.forename: Kwan-Dun
authors.initials: KD
authors.lastname: Wu
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D007676:Kidney Failure, Chronic / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012079:Renal Circulation; D006435:Renal Dialysis