Folic acid supplementation with and without vitamin B6 and revascularization risk: a meta-analysis of randomized controlled trials.

Qin X., Fan F., Cui Y., Chen F., Chen Y., Cheng X., Li Y., Wang B., Xu X., Xu X., Huo Y., Wang X.

BACKGROUND & AIMS: There is a growing amount of data and a continuing controversy over the effect of folic acid supplementation with and without vitamin B6 on revascularization risk. METHODS: We conducted a meta-analysis based on up-to-date published relevant randomized trials to further examine this issue. Relative risk (RR) was used to measure the effect of folic acid supplementation on risk of revascularization using a random-effects model. Total revascularization was defined as any arterial revascularization. Restenosis was defined as stenosis of more than 50 percent of the luminal diameter. RESULTS: Overall, folic acid supplementation had no significant effect on coronary revascularization (9 trials, n = 27,418, RR = 0.99; 95%CI:0.88-1.11, P = 0.88), coronary artery bypass grafting (CABG) (5 trials, n = 10,703, 0.90; 0.79-1.03, P = 0.11), percutaneous coronary intervention (PCI) (5 trials, n = 10,703, 1.05; 0.89-1.23, P = 0.59), coronary restenosis (3 trials, n = 926, 1.05; 0.89-1.23, P = 0.59) or total revascularization (7 trials, n = 29,314, 1.06; 95%CI: 0.99-1.13, P = 0.10). However, a greater beneficial effect was observed for coronary revascularization among those trials with a moderate dose of vitamin B6 (5-10 mg/d; RR: 0.47; 95%CI: 0.28-0.80, P = 0.005), but not in trials without vitamin B6 or with a high dose of vitamin B6. And a non-significant greater total revascularization risk was observed in trials with a higher folic acid dose (>2 mg/d, RR = 1.11; 95%CI: 0.98-1.25, P = 0.09; ≥5 mg/d, RR = 1.98; 95%CI: 0.93-4.20, P = 0.08). CONCLUSIONS: Our analyses indicate that folic acid supplementation has no significant effect on coronary revascularization, CABG, PCI, coronary restenosis or total revascularization. However, a combination of folic acid and moderate vitamin B6 may be beneficial in reducing coronary revascularization risk.

DOI

10.1016/j.clnu.2014.01.006

Type

Journal article

Publication Date

2014-08-01T00:00:00+00:00

Volume

33

Pages

603 - 612

Total pages

9

Keywords

Folic acid supplementation, Meta-analysis, Randomized controlled trials, Revascularization risk, Coronary Artery Bypass, Coronary Restenosis, Databases, Factual, Dietary Supplements, Folic Acid, Humans, Randomized Controlled Trials as Topic, Risk Factors, Vitamin B 6

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