Efficacy of folic acid supplementation on endothelial function and plasma homocysteine concentration in coronary artery disease: A meta-analysis of randomized controlled trials
What this study found
High-dose folic acid improved endothelial function and lowered plasma homocysteine in coronary artery disease, with the clearest benefit seen for flow-mediated dilation. Folic acid increased flow-mediated dilation (MD 57.72 µm; 95% CI 50.14 to 65.31; P<0.05; I2=0%) and reduced plasma homocysteine (MD -3.66 µmol/L; 95% CI -5.44 to -1.87; P<0.05), but did not significantly change endothelium-dependent dilation, GTN diameter change, heart rate, hyperemic flow, or blood pressure. The authors concluded that 5 mg/day folic acid for more than four weeks may improve endothelial function in CAD,…
- Study & population
- Meta-analysis of six randomized controlled trials in adults with coronary artery disease.
- Intervention
- Folic acid was given orally at 5 mg/day, taken daily for more than 4 weeks and up to 16 weeks.
- Key limitation
- Evidence was based on only six trials with a modest pooled sample size and short treatment durations of eight weeks to four months.
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Open PDFOriginal abstract
The aim of the present study was to conduct an updated meta-analysis of relevant randomized controlled trials (RCTs) in order to estimate the effect of folic acid supplementation on endothelial function and the concentration of plasma homocysteine in patients with coronary artery disease (CAD). An extensive search of PubMed was conducted to identify RCTs that compared folic acid with placebo therapy. The mean difference (MD) and 95% confidence interval (CI) were used as a measure of the correlation between folic acid supplementation and endothelial function/plasma homocysteine concentration. Of the 377 patients included in this analysis, 191 patients underwent folic acid supplementation and 186 individuals underwent placebo treatment. Compared with the use of a placebo, folic acid supplementation alone exhibited significant efficacy on increasing flow-mediated dilation (FMD; MD, 57.72 μm; 95% CI, 50.14–65.31; P<0.05) and lowering the concentration of plasma homocysteine (MD, −3.66 μmol/l; 95% CI, −5.44–−1.87; P<0.05; I2, 87%). There was no significant change in the response to end diastolic diameter, glyceryl-trinitrate diameter, heart rate, baseline and peak hyperemic flow and systolic and diastolic blood pressure between the folic acid and placebo groups (P>0.05). Therefore, the meta-analysis indicated that 5 mg folic acid daily supplementation for >4 weeks significantly improved FMD and lowered the concentration of plasma homocysteine in patients with CAD. However, more RCTs are required in order to confirm these observations.