Effect of folic acid and B vitamins on risk of cardiovascular events and total mortality among women at high risk for cardiovascular disease: a randomized trial
| Autor: | Elaine Zaharris, Julie E. Buring, Nancy R. Cook, JoAnn E. Manson, Christine M. Albert, Eleanor Danielson, J. Michael Gaziano, Jean G. MacFadyen |
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| Rok vydání: | 2008 |
| Předmět: |
Vitamin
Adult Risk medicine.medical_specialty Placebo Article law.invention chemistry.chemical_compound Folic Acid Randomized controlled trial Double-Blind Method law Internal medicine medicine Humans Vitamin B12 Risk factor Homocysteine Aged Polycap business.industry General Medicine Middle Aged Vitamin B 6 Surgery B vitamins Drug Combinations Vitamin B 12 chemistry Cardiovascular Diseases Relative risk Dietary Supplements Vitamin B Complex Female business |
| Zdroj: | JAMA. 299(17) |
| ISSN: | 1538-3598 |
| Popis: | Recent randomized trials among patients with preexisting cardiovascular disease (CVD) have failed to support benefits of B-vitamin supplementation on cardiovascular risk. Observational data suggest benefits may be greater among women, yet women have been underrepresented in published randomized trials.To test whether a combination of folic acid, vitamin B6, and vitamin B12 lowers risk of CVD among high-risk women with and without CVD.Within an ongoing randomized trial of antioxidant vitamins, 5442 women who were US health professionals aged 42 years or older, with either a history of CVD or 3 or more coronary risk factors, were enrolled in a randomized, double-blind, placebo-controlled trial to receive a combination pill containing folic acid, vitamin B6, and vitamin B12 or a matching placebo, and were treated for 7.3 years from April 1998 through July 2005.Daily intake of a combination pill of 2.5 mg of folic acid, 50 mg of vitamin B6, and 1 mg of vitamin B12.A composite outcome of myocardial infarction, stroke, coronary revascularization, or CVD mortality.Compared with placebo, a total of 796 women experienced a confirmed CVD event (406 in the active group and 390 in the placebo group). Patients receiving active vitamin treatment had similar risk for the composite CVD primary end point (226.9/10,000 person-years vs 219.2/10,000 person-years for the active vs placebo group; relative risk [RR], 1.03; 95% confidence interval [CI], 0.90-1.19; P = .65), as well as for the secondary outcomes including myocardial infarction (34.5/10,000 person-years vs 39.5/10,000 person-years; RR, 0.87; 95% CI, 0.63-1.22; P = .42), stroke (41.9/10,000 person-years vs 36.8/10,000 person-years; RR, 1.14; 95% CI, 0.82-1.57; P = .44), and CVD mortality (50.3/10,000 person-years vs 49.6/10,000 person-years; RR, 1.01; 95% CI, 0.76-1.35; P = .93). In a blood substudy, geometric mean plasma homocysteine level was decreased by 18.5% (95% CI, 12.5%-24.1%; P.001) in the active group (n = 150) over that observed in the placebo group (n = 150), for a difference of 2.27 micromol/L (95% CI, 1.54-2.96 micromol/L).After 7.3 years of treatment and follow-up, a combination pill of folic acid, vitamin B6, and vitamin B12 did not reduce a combined end point of total cardiovascular events among high-risk women, despite significant homocysteine lowering.clinicaltrials.gov Identifier: NCT00000541. |
| Databáze: | OpenAIRE |
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