Folic acid supplementation may dramatically reduce the risk of first stroke in patients with hypertension, low platelet count and high homocysteine levels, suggests a study published online May 7 in the Journal of the American College of Cardiology.
Senior author Yong Huo, MD, and colleagues studied 10,789 hypertensive adults from the China Stroke Primary Prevention Trial, which randomized participants to either 10 mg of enalapril alone or 10 mg enalapril plus 0.8 mg folic acid. Both treatments required a single pill per day.
The researchers found the individuals with the lowest platelet counts and the highest homocysteine levels were at the greatest risk of stroke—5.6 percent experienced a first stroke in the 4.2 years of follow-up. However, those taking folic acid supplements were 73 percent less likely to experience stroke than those taking only enalapril.
Folic acid supplementation wasn’t associated with a decreased risk of stroke for the lowest-risk group (high platelets, low homocysteine levels).
“Our analysis has shown that baseline low platelet count and elevated homocysteine can jointly increase the risk of first stroke,” Huo, director of the Heart Center of Peking University First Hospital in China, said in a press release. “If the findings are further confirmed by prospective trials, we can raise the prospect that we can identify patients at high risk of developing first stroke by measuring both platelet and homocysteine, and we can remarkably lower stroke risk among this subgroup of patients with folic acid—a simple, safe and inexpensive treatment.”
Stroke is the top cause of death in China and the second-leading cause of death worldwide, the authors noted. About 77 percent of strokes are first events, necessitating improved primary prevention.
According to the authors, this is the largest study of its kind devoted to the primary prevention of stroke. They said their Chinese study population was uniquely set up to examine the effect of low platelet and elevated homocysteine levels because China doesn’t have mandatory folic acid fortification for its grain products and has a low rate of folic acid supplementation. In addition, the low consumption of folate-containing foods and high prevalence of the MTHFR C677T gene mutation—which has been found in a quarter of the Chinese population compared to 10 to 12 percent of Americans—may also contribute to a higher likelihood of low platelet counts and elevated homocysteine.
For these reasons, Huo and colleagues noted it may be difficult to generalize their findings to other regions. But the identification of a subset of patients who may benefit most from folic acid could have widespread utility, they said.
“If confirmed, these results have enormous public health implications given the high incident rate of stroke in many developing countries, in addition to China,” Huo said. “Based on our findings, we can detect hypertensive adults at particular high risk of stroke and incorporate a folic acid supplement tailored to individual genetic, nutritional and clinical characteristics. We are on the right path to figuring out cost-effective primary prevention strategies for stroke in China and beyond.”