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Randomized controlled trial of homocysteine-lowering vitamin treatment in elderly patients with vascular disease

Stott, David J, MacIntosh, Graham, Lowe, Gordon DO, Rumley, Ann, McMahon, Alex D, Langhorne, Peter, Tait, R Campbell, O'Reilly, Denis St J, Spilg, Edward G, MacDonald, Jonathan B, MacFarlane, Peter W, Westendorp, Rudi GJ
American journal of clinical nutrition 2005 v.82 no.6 pp. 1320-1326
elderly nutrition, elderly, myocardial infarction, vitamin supplements, folic acid, vitamin B12, riboflavin, pyridoxine, randomized clinical trials, dose response, blood serum, homocysteine, fibrinogen, blood coagulation factors, consciousness
BACKGROUND: Homocysteine is an independent risk factor for vascular disease and is associated with dementia in older people. Potential mechanisms include altered endothelial and hemostatic function. OBJECTIVE: We aimed to determine the effects of folic acid plus vitamin B-12, riboflavin, and vitamin B-6 on homocysteine and cognitive function. DESIGN: This was a factorial 2 x 2 x 2, randomized, placebo-controlled, double-blind study with 3 active treatments: folic acid (2.5 mg) plus vitamin B-12 (500 [micro]g), vitamin B-6 (25 mg), and riboflavin (25 mg). We studied 185 patients aged [>/=]65 y with ischemic vascular disease. Outcome measures included plasma homocysteine, fibrinogen, and von Willebrand factor at 3 mo and cognitive change (determined with the use of the Letter Digit Coding Test and on the basis of the Telephone Interview of Cognitive Status) after 1 y. RESULTS: The mean (±SD) baseline plasma homocysteine concentration was 16.5 ± 6.4 [micro]mol/L. This value was 5.0 (95% CI: 3.8, 6.2) [micro]mol/L lower in patients given folic acid plus vitamin B-12 than in patients not given folic acid plus vitamin B-12 but did not change significantly with vitamin B-6 or riboflavin treatment. Homocysteine lowering with folic acid plus vitamin B-12 had no significant effect, relative to the 2 other treatments, on fibrinogen, von Willebrand factor, or cognitive performance as measured by the Letter Digit Coding Test (mean change: -1; 95% CI: -2.3, 1.4) and the Telephone Interview of Cognitive Status (-0.7; 95% CI: -1.7, 0.4). CONCLUSION: Oral folic acid plus vitamin B-12 decreased homocysteine concentrations in elderly patients with vascular disease but was not associated with statistically significant beneficial effects on cognitive function over the short or medium term.