title: Short daily versus conventional hemodialysis for hypertensive patients: a randomized cross-over study.
abstract: BACKGROUND
  Treatment of end stage renal disease patients with short daily hemodialysis has been associated with an improvement in blood pressure. It is unclear from these studies if anti-hypertensive management had been optimized prior to starting short daily hemodialysis. Also, the potential mechanism(s) of blood pressure improvement remain to be fully elucidated.
  We undertook a randomized cross-over trial in adult hypertensive patients with ESRD treated with conventional hemodialysis to determine: 1) if short-daily hemodialysis is associated with a reduction in systolic blood pressure after a 3-month blood pressure optimization period and; 2) the potential mechanism(s) of blood pressure reduction. Blood pressure was measured using Canadian Hypertension Education Program guidelines. Extracellular fluid volume (ECFV) was assessed with bioimpedance. Serum catecholamines were used to assess the sympathetic nervous system. Interleukin-6 (IL-6) and thiobarbituric acid reactive substances (T-BARS) were used as markers of inflammation and oxidative stress respectively.
  
  
  RESULTS
  After a 3-month run-in phase in which systolic blood pressure improved, there was no significant difference in pre-dialysis systolic pressure between short-daily and conventional hemodialysis (p = 0.39). However, similar blood pressures were achieved on fewer anti-hypertensive medications with short daily hemodialysis compared to conventional hemodialysis (p = 0.01). Short daily hemodialysis, compared to conventional hemodialysis, was not associated with a difference in dry weight or ECFV (p = 0.77). Sympathetic nervous system activity as assessed by plasma epinephrine (p = 1.0) and norepinephrine (p = 0.52) was also not different. Markers of inflammation (p = 0.42) and oxidative stress (p = 0.83) were also similar between the two treatment arms.
  
  
  CONCLUSIONS
  Patients treated with short daily, compared to conventional hemodialysis, have similar blood pressure control on fewer anti-hypertensive medications. The mechanism(s) by which short daily hemodialysis allows for decreased anti-hypertensive medication use remains unclear but effects on sodium balance and changes in peripheral vascular resistance require further study.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT00759967.
authors.affiliation: Associate Professor of Medicine, Division of Nephrology, Ottawa Hospital, Kidney Research Centre of the Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Zimmerman
authors.affiliation: Associate Professor of Medicine, Division of Nephrology, Ottawa Hospital, Kidney Research Centre of the Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Marcel
authors.initials: M
authors.lastname: Ruzicka
authors.affiliation: Professor of Medicine, Surgery, Anesthesia and Epidemiology, University of Ottawa; Senior Scientist, Clinical Epidemiology, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Hebert
authors.affiliation: Associate Professor, Departments of Medicine, Surgery, Epidemiology and Community Medicine, Senior Scientist and Director, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Dean
authors.initials: D
authors.lastname: Fergusson
authors.affiliation: Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Rhian M
authors.initials: RM
authors.lastname: Touyz
authors.affiliation: Professor of Medicine, Division of Nephrology, Senior Scientist, Kidney Research Centre of the Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Burns
mesh_terms: D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000188:drug therapy; D015850:Interleukin-6 / Q000097:blood; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents; D015850:Interleukin-6