Limits...
Folic Acid Supplementation and the Risk of Cardiovascular Diseases: A Meta ‐ Analysis of Randomized Controlled Trials

View Article: PubMed Central - PubMed

ABSTRACT

Background: Results from observational and genetic epidemiological studies suggest that lower serum homocysteine levels are associated with lower incidence of cardiovascular disease (CVD). Numerous randomized controlled trials have investigated the efficacy of lowering homocysteine with folic acid supplementation for CVD risk, but conflicting results have been reported.

Methods and results: Three bibliographic databases (Medline, Embase, and the Cochrane Database of Systematic Reviews) were searched from database inception until December 1, 2015. Of the 1933 references reviewed for eligibility, 30 randomized controlled trials involving 82 334 participants were included in the final analysis. The pooled relative risks of folic acid supplementation compared with controls were 0.90 (95% CI 0.84–0.96; P=0.002) for stroke, 1.04 (95% CI 0.99–1.09; P=0.16) for coronary heart disease, and 0.96 (95% CI 0.92–0.99; P=0.02) for overall CVD. The intervention effects for both stroke and combined CVD were more pronounced among participants with lower plasma folate levels at baseline (both P<0.02 for interaction). In stratified analyses, a greater beneficial effect for overall CVD was seen in trials among participants without preexisting CVD (P=0.006 for interaction) or in trials with larger reduction in homocysteine levels (P=0.009 for interaction).

Conclusions: Our meta‐analysis indicated a 10% lower risk of stroke and a 4% lower risk of overall CVD with folic acid supplementation. A greater benefit for CVD was observed among participants with lower plasma folate levels and without preexisting CVD and in studies with larger decreases in homocysteine levels. Folic acid supplementation had no significant effect on risk of coronary heart disease.

No MeSH data available.


Related in: MedlinePlus

Relative risk estimates for coronary heart disease (folic acid supplementation vs control) by individual trials and pooled results. RCT indicates randomized controlled trial.
© Copyright Policy - creativeCommonsBy-nc
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5015297&req=5

jah31707-fig-0003: Relative risk estimates for coronary heart disease (folic acid supplementation vs control) by individual trials and pooled results. RCT indicates randomized controlled trial.

Mentions: In 25 trials, 5899 CHD events were reported among 78 192 participants (Figure 3). Across all 25 trials, the average incidence rate for CHD was 7.7% (3091 events in 40 004 participants) in the folic acid supplementation group and 7.4% (2808 events in 38 188 participants) in the control group. Only 1 individual study (Lange et al41) observed a significantly increased risk of CHD with supplementation of folic acid (Figure 3). The pooled RR for CHD comparing folic acid supplementation with the control group was 1.04 (95% CI 0.99–1.09, P=0.16) in both the fixed‐ and random‐effects models (Figure 3). The result did not differ significantly across subgroups (all P>0.15 for interaction) (Table 3).


Folic Acid Supplementation and the Risk of Cardiovascular Diseases: A Meta ‐ Analysis of Randomized Controlled Trials
Relative risk estimates for coronary heart disease (folic acid supplementation vs control) by individual trials and pooled results. RCT indicates randomized controlled trial.
© Copyright Policy - creativeCommonsBy-nc
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5015297&req=5

jah31707-fig-0003: Relative risk estimates for coronary heart disease (folic acid supplementation vs control) by individual trials and pooled results. RCT indicates randomized controlled trial.
Mentions: In 25 trials, 5899 CHD events were reported among 78 192 participants (Figure 3). Across all 25 trials, the average incidence rate for CHD was 7.7% (3091 events in 40 004 participants) in the folic acid supplementation group and 7.4% (2808 events in 38 188 participants) in the control group. Only 1 individual study (Lange et al41) observed a significantly increased risk of CHD with supplementation of folic acid (Figure 3). The pooled RR for CHD comparing folic acid supplementation with the control group was 1.04 (95% CI 0.99–1.09, P=0.16) in both the fixed‐ and random‐effects models (Figure 3). The result did not differ significantly across subgroups (all P>0.15 for interaction) (Table 3).

View Article: PubMed Central - PubMed

ABSTRACT

Background: Results from observational and genetic epidemiological studies suggest that lower serum homocysteine levels are associated with lower incidence of cardiovascular disease (CVD). Numerous randomized controlled trials have investigated the efficacy of lowering homocysteine with folic acid supplementation for CVD risk, but conflicting results have been reported.

Methods and results: Three bibliographic databases (Medline, Embase, and the Cochrane Database of Systematic Reviews) were searched from database inception until December 1, 2015. Of the 1933 references reviewed for eligibility, 30 randomized controlled trials involving 82 334 participants were included in the final analysis. The pooled relative risks of folic acid supplementation compared with controls were 0.90 (95% CI 0.84–0.96; P=0.002) for stroke, 1.04 (95% CI 0.99–1.09; P=0.16) for coronary heart disease, and 0.96 (95% CI 0.92–0.99; P=0.02) for overall CVD. The intervention effects for both stroke and combined CVD were more pronounced among participants with lower plasma folate levels at baseline (both P<0.02 for interaction). In stratified analyses, a greater beneficial effect for overall CVD was seen in trials among participants without preexisting CVD (P=0.006 for interaction) or in trials with larger reduction in homocysteine levels (P=0.009 for interaction).

Conclusions: Our meta‐analysis indicated a 10% lower risk of stroke and a 4% lower risk of overall CVD with folic acid supplementation. A greater benefit for CVD was observed among participants with lower plasma folate levels and without preexisting CVD and in studies with larger decreases in homocysteine levels. Folic acid supplementation had no significant effect on risk of coronary heart disease.

No MeSH data available.


Related in: MedlinePlus