title: Randomized trial of FX high flux vs standard high flux dialysis for homocysteine clearance.
abstract: BACKGROUND
  Cardiovascular disease is the major cause of death in the end-stage renal disease population. Novel risk factors such as homocysteine (Hcy) are of considerable interest in this group as hyperhomocysteinaemia is highly prevalent in the setting of renal impairment. Folic acid-vitamin B group therapies are only partially effective treatments. Hcy is highly protein-bound and thus poorly dialysed. Dialyzers with albumin-leaking properties have been shown to result in lowering of plasma Hcy. As the FX-class (Advanced Fresenius Polysulfone dialyzer) has greater clearance of larger molecular weight substances but is non-albumin-leaking, we explored the capacity of this new technology membrane to reduce plasma Hcy levels.
  
  
  METHODS
  A prospective randomized cross-over trial in 35 prevalent haemodialysis patients, one group receiving 12 weeks dialysis using FX dialyzer then 12 weeks with standard high flux dialysis (SHF) and the other group SHF followed by FX dialyzer. All patients received vitamin B(6) 25 mg and folic acid 5 mg daily throughout the study.
  
  
  RESULTS
  The primary outcome was plasma Hcy pre-dialysis at week 12. FX vs SHF showed no significant difference, 25+/-6.6 vs 25.9+/-5.8 microg/l, Delta95% CI = -2.77 to 4.59, P = 0.31. There was a non-significant trend toward a decrease in Hcy in both groups (27.43+/-7.68 to 25.91+/-5.78 micromol/l for SHF, P = 0.23 and 26.0+/-4.58 to 25.0+/-6.61 micromol/l for FX, P = 0.28). Analysis by repeated measures method demonstrated a statistically significantly lower Hcy with FX vs SHF dialyzer (adjusted beta = -1.30, 95% CI = -2.41 to -0.19, P = 0.022). K(t)/V(urea) was higher in FX vs SHF (1.35+/-0.18 vs 1.22+/-0.2; P = 0.013). Folate and B(6) levels did not change.
  
  
  CONCLUSIONS
  The primary outcome analysis did not show any significant difference in pre-Hcy comparing FX and SHF membranes. Although our secondary analysis demonstrated a statistically significant difference between membranes, the magnitude of the difference (1.3 mumol/l) is not clinically significant. Thus the use of the FX dialyzer did not result in a clinically significant benefit in relation to improving pre-dialysis Hcy compared with standard high-flux dialysis.
authors: Department of Nephrology, Level 2, ARTS Building, Princess Alexandra Hospital, Ipswich Road, Woolloongabba, Queensland, Australia 4207.
authors: David W
authors: DW
authors: Mudge
authors: Robyn
authors: R
authors: Rogers
authors: Peter
authors: P
authors: Hollett
authors: Belinda
authors: B
authors: Law
authors: Kylie
authors: K
authors: Reiger
authors: James J B
authors: JJ
authors: Petrie
authors: Lee
authors: L
authors: Price
authors: David W
authors: DW
authors: Johnson
authors: Scott B
authors: SB
authors: Campbell
authors: Nicole M
authors: NM
authors: Isbel
authors: Matthew
authors: M
authors: Sullivan
authors: Carmel M
authors: CM
authors: Hawley
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology; D018592:Cross-Over Studies; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications / Q000628:therapy; D007688:Kidneys, Artificial; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D006435:Renal Dialysis / Q000379:methods*; D013997:Time Factors
chemical_list: D006710:Homocysteine