The effects of high-dose folic acid on blood pressure of hypertensive adults with hyperhomocysteinemia: A randomized double- blind placebo controlled clinical trial (Tehran Homocysteine Survey)

Abstract

Background: An elevated homocysteine concentration is associated with increased risk of hypertension. Although both low- and high-dose folate reduce blood homocysteine levels significantly, the relative effects of different doses of folate on blood pressure is not well established yet. In this study we investigated the effects of administrating high-dose folic acid on homocysteine and blood pressure of hyperhomocysteinemic persons.

Methods: Forty-two individuals with hypertension and moderate/intermediate hyperhomocysteinemia received either 5 mg/day folic acid or placebo for six weeks. Baseline and 6^th week blood pressures, homocysteine, folate and Vitamin B12 levels were measured.

Results: Systolic blood pressure reduced significantly while decrease in diastolic blood pressure was not significant in folic acid compared to the placebo group (P=0.001 and P=0.17, respectively; ANOVA). Homocysteine decreased while folate increased significantly in folic acid relative to placebo group (P=0.04 and P=0.002, respectively; ANOVA]. Changes in folic acid concentrations were significantly and negatively correlated with changes in systolic blood pressure (P=0.02, r = -0.51, Pearson's correlation coefficient).

Conclusion: Short-term high-dose supplementation with folic acid is effective in reduction of systolic blood pressure in hypertensive hyperhomocysteinemic subjects.