This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Objective We evaluated the interaction of serum folate and vitamin B12 with methylenetetrahydrofolate reductase (MTHFR) C677T genotypes on the risk of first ischemic stroke and on the efficacy of folic acid treatment in prevention of first ischemic stroke.
Methods A total of 20,702 hypertensive adults were randomized to a double-blind treatment of daily enalapril 10 mg and folic acid 0.8 mg or enalapril 10 mg alone. Participants were followed up every 3 months.
Results Median values of folate and B12 concentrations at baseline were 8.1 ng/mL and 280.2 pmol/L, respectively. Over a median of 4.5 years, among those not receiving folic acid, participants with baseline serum B12 or serum folate above the median had a significantly lower risk of first ischemic stroke (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.57–0.96), especially in those with MTHFR 677 CC genotype (wild-type) (HR, 0.49; 95% CI, 0.31–0.78). Folic acid treatment significantly reduced the risk of first ischemic stroke in participants with both folate and B12 below the median (2.3% in enalapril-folic acid group vs 3.6% in enalapril-only group; HR, 0.62; 95% CI, 0.46–0.86), particularly in MTHFR 677 CC carriers (1.6% vs 4.9%; HR, 0.24; 95% CI, 0.11–0.55). However, TT homozygotes responded better with both folate and B12 levels above the median (HR, 0.28; 95% CI, 0.10–0.75).
Conclusions The risk of first ischemic stroke was significantly higher in hypertensive patients with low levels of both folate and B12. Effect of folic acid treatment was greatest in patients with low folate and B12 with the CC genotype, and with high folate and B12 with the TT genotype.
Glossary
- CI=
- confidence interval;
- CSPPT=
- China Stroke Primary Prevention Trial;
- HR=
- hazard ratio;
- IQR=
- interquartile range;
- MI=
- myocardial infarction;
- MTHFR=
- methylenetetrahydrofolate reductase;
- tHcy=
- total homocysteine
Footnotes
Go to Neurology.org/N for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
- Received June 8, 2020.
- Accepted in final form September 19, 2020.
- © 2020 American Academy of Neurology
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
Disputes & Debates: Rapid online correspondence
NOTE: All authors' disclosures must be entered and current in our database before comments can be posted. Enter and update disclosures at http://submit.neurology.org. Exception: replies to comments concerning an article you originally authored do not require updated disclosures.
- Stay timely. Submit only on articles published within the last 8 weeks.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- 200 words maximum.
- 5 references maximum. Reference 1 must be the article on which you are commenting.
- 5 authors maximum. Exception: replies can include all original authors of the article.
- Submitted comments are subject to editing and editor review prior to posting.