Folic acid lowers risk of first stroke associated with diabetes
An association exists between an increased risk of first stroke and diabetes or a fasting blood glucose (FBG) ≥7.0 mmol/L in Chinese hypertensive adults, a recent study has found. In addition, folic acid treatment can reduce this elevated risk by 34 percent.
“Diabetes is a known risk factor for stroke, but data on its prospective association with first stroke are limited,” researchers said. “Folic acid supplementation has been shown to protect against first stroke, but its role in preventing first stroke in diabetes is unknown.”
To test these hypotheses, a post hoc analysis of the China Stroke Primary Prevention Trial was conducted. This analysis involved hypertensive adults (n=20,327) without a history of stroke or myocardial infarction, who were randomly assigned to a double-blind daily treatment with 10 mg enalapril and 0.8 mg folic acid (n=10,160) or 10 mg enalapril (n=10,167).
Researchers used Kaplan-Meier survival analysis and Cox proportionate hazard models to test the hypotheses with adjustment for pertinent covariables. Median treatment duration was 4.5 years.
A total of 616 participants experienced a first stroke (497 ischaemic strokes) during treatment. Compared with a low FBG concentration (<5.0 mmol/L), a high FBG concentration (≥7.0 mmol/L) or diabetes was associated with an elevated risk of first stroke (2.6 vs 6.0 percent; hazard ratio [HR], 1.9; 95 percent CI, 1.3 to 2.8; p<0.001).
Treatment with folic acid attenuated the risk of stroke across a wide range of FBG concentrations ≥5.0 mmol/L, but its benefit was more pronounced among patients with FBG concentrations ≥7.0 mmol/L or with diabetes (HR, 0.66; 0.46 to 0.97; p<0.05). A significant interactive effect of FBG and folic acid treatment was observed on first stroke (p=0.01).
Researchers noted that additional research is warranted to confirm these findings.