title: The effect of homocysteine reduction by B-vitamin supplementation on markers of endothelial dysfunction.
abstract: Hyperhomocysteinemia is a risk factor for arterial vascular disease and venous thrombosis. The pathophysiology of this relation is unclear, but several studies suggest that hyperhomocysteinemia impairs endothelial function. We examined the effect of homocysteine lowering by B-vitamin supplementation on tissue plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI) and von Willebrand factor (vWf)--markers of endothelial dysfunction--in hyperhomocysteinemic and normohomocysteinemic volunteers. A total of 123 healthy volunteers were randomized to placebo or B-vitamins (5 mg folic acid, 0.4 mg hydroxycobalamin and 50 mg pyridoxine) daily for 8 weeks. Before and after the intervention period, blood samples were taken for measurements of homocysteine, tPA, PAI and vWf. There was no evident association between homocysteine concentration and concentrations of markers of endothelial dysfunction at baseline. The mean reduction of homocysteine concentration was 31% (95%CI 22.7 to 39.1) in the B-vitamin group compared to 3% reduction in the placebo group. Concentrations of tPA, PAI and vWf did not change after supplementation of B-vitamins. In conclusion, the results of our study show that homocysteine reduction by B-vitamin supplementation has no effect on markers of endothelial dysfunction in healthy volunteers.
authors.affiliation: Department of Endocrinology, University Medical Centre Nijmegen, The Netherlands.
authors.forename: Anita C T M
authors.initials: AC
authors.lastname: Peeters
authors.forename: Els F
authors.initials: EF
authors.lastname: van der Molen
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Blom
authors.forename: Martin
authors.initials: M
authors.lastname: den Heijer
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects / Q000473:pathology*; D005260:Female; D006710:Homocysteine / Q000097:blood* / Q000187:drug effects; D006801:Humans; D006879:Hydroxocobalamin / Q000008:administration & dosage* / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D011736:Pyridoxine / Q000008:administration & dosage* / Q000494:pharmacology; D010959:Tissue Plasminogen Activator / Q000097:blood; D014841:von Willebrand Factor / Q000032:analysis
chemical_list: D015415:Biomarkers; D017395:Plasminogen Activator Inhibitor 1; D014841:von Willebrand Factor; D006710:Homocysteine; D010959:Tissue Plasminogen Activator; D011736:Pyridoxine; D006879:Hydroxocobalamin