title: Long-term reduction of plasma homocysteine levels by super-flux dialyzers in hemodialysis patients.
abstract: BACKGROUND
  Hyperhomocysteinemia is an independent risk factor for cardiovascular disease in chronic hemodialysis (CHD) patients. Treatment with folic acid normalizes total homocysteine (tHcy) in only a minority of the patients. The present investigation has been conducted to study the influence of various dialyzers with different flux characteristics on the reduction of tHcy in the long term.
  
  
  METHODS
  Total Hcy, folate, vitamin B6, vitamin B12, and albumin levels were assessed prospectively in 10 patients undergoing HD with high-flux polysulfon (PS; F 60) and 20 patients with super-flux dialyzers (N = 10 PS, F 500S; N = 10 CTA, Tricea 150G). Blood samples were collected before hemodialysis both at the beginning of the study and after 12 weeks.
  
  
  RESULTS
  At baseline, all the groups showed similar tHcy levels. During high-flux dialysis, tHcy remained stable. In contrast, during dialysis with both super-flux modalities, tHcy decreased significantly (F 500S week 1, 29.6 +/- 9.9 micromol/L, and week 12, 21.5 +/- 8.5 micromol/L, P = 0.007; Tricea 150G week 1, 24.4 +/- 8.7 micromol/L, and week 12, 15.3 +/- 3.7 micromol/L, P = 0.008). The difference between high-flux and super-flux dialyzers was highly significant (mean: high-flux increase 15.6%, super-flux decrease 33. 3%, P = 0.001). Multivariate analysis showed a significant effect of super-flux dialysis on tHcy (P = 0.001), independently of the previously mentioned variables.
  
  
  CONCLUSIONS
  Our findings clearly show that both types of super-flux dialyzers reduced tHcy significantly. As the molecular weight of free homocysteine is less than 268 D, the most likely explanation seems to be the removal of uremic toxins with inhibitory activities against enzymes involved in the extrarenal homocysteine metabolism.
authors.affiliation: Departments of Nephrology and Clinical Chemistry, Medical Center Alkmaar, Alkmaar, The Netherlands. avantellingen@worldmail.nl
authors.forename: A
authors.initials: A
authors.lastname: Van Tellingen
authors.forename: M P
authors.initials: MP
authors.lastname: Grooteman
authors.forename: P C
authors.initials: PC
authors.lastname: Bartels
authors.forename: J
authors.initials: J
authors.lastname: Van Limbeek
authors.forename: C
authors.initials: C
authors.lastname: Van Guldener
authors.forename: P M
authors.initials: PM
authors.lastname: Wee
authors.forename: M J
authors.initials: MJ
authors.lastname: Nubé
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005492:Folic Acid / Q000097:blood; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011736:Pyridoxine / Q000097:blood; D006435:Renal Dialysis / Q000295:instrumentation*; D012709:Serum Albumin / Q000032:analysis; D013997:Time Factors; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D012709:Serum Albumin; D006710:Homocysteine; D005492:Folic Acid; D011736:Pyridoxine; D014805:Vitamin B 12