Open AccessEfficacy of folic acid supplementation in stroke prevention: new insight from a meta‐analysis
Author(s) -
Huo Y.,
Qin X.,
Wang J.,
Sun N.,
Zeng Q.,
Xu X.,
Liu L.,
Xu X.,
Wang X.
Publication year - 2012
Publication title -
international journal of clinical practice
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.756
H-Index - 98
eISSN - 1742-1241
pISSN - 1368-5031
DOI - 10.1111/j.1742-1241.2012.02929.x
Subject(s) - medicine , stroke (engine) , folic acid , meta analysis , relative risk , folic acid supplementation , randomized controlled trial , clinical trial , confidence interval , mechanical engineering , engineering
Summary Aims: There are growing data and a continuing controversy over the efficacy of folic acid supplementation in stroke prevention. We conducted a meta‐analysis based on relevant, up‐to‐date published randomised trials to further examine this issue. Methods: Relative risk (RR) was used to measure the effect of folic acid supplementation on risk of stroke with a fixed‐effects model. Results: Overall, folic acid supplementation reduced the risk of stroke by 8% ( n = 55,764; RR: 0.92; 95% CI: 0.86–1.00, p = 0.038). In the 10 trials with no or partial folic acid fortification ( n = 43,426), the risk of stroke was reduced by 11% (0.89; 0.82–0.97, p = 0.010). Within these trials, a greater beneficial effect was observed among trials with a lower percent use of statins [≤ 80% (median); 0.77; 0.64–0.92, p = 0.005], and a meta‐regression analysis also suggested a positive dose‐response relationship between percent use of statins and log‐RR for stroke associated with folic acid supplementation (p = 0.013). A daily dose of 0.4–0.8mg folic acid appeared to be adequate for stroke prevention in comparison with larger doses. In the remaining five trials conducted in populations with folic acid fortification ( n = 12,338), folic acid supplementation had no effect on stroke risk (1.03; 0.88–1.21, p = 0.69). Conclusions: Our analysis indicated that folic acid supplementation is effective in stroke prevention in populations with no or partial folic acid fortification. In addition, a greater beneficial effect was observed among trials with a lower percent use of statins. Our findings underscore the importance of identifying target populations that can particularly benefit from folic acid therapy.