Changes of homocysteine levels and arterial endothelial function in patients with high risk of coronary artery disease after 6-month folic acid supplementation

Abstract

Objectives — This study aimed to assess whether folic acid supplementation could produce longer-term (6-month) improvements in homocysteine levels and arterial endothelial function in patients with a high risk (3 or more traditional risk factors) of coronary artery disease (CAD) and hyperhomocysteinaemia.

Methods — Thirty-one adults with 3 or more traditional risk factors of CAD and hyperhomocysteinaemia were selected, without CAD (the criterion of CAD is that more than one main vessel has an obstruction ≥ 50%) by coronary angiography. All subjects were given folic acid (5 mg/day) for 6 months. Fasting plasma homocysteine levels were measured by high-performance liquid chromatography. Plasma folic acid and vitamin B12 levels were measured with immunoassay. Arterial endothelial function was measured as flow-mediated dilation of the brachial artery using high-resolution B-mode ultrasound.

Results — Folic acid supplementation for 6 months was associated with a significant increase in mean (± SD) plasma levels of folic acid (4.6 ± 1.4 μg/l to 9.1 ± 2.5 μg/l; P < 0.01) and a significant decline in homocysteine levels (18.3 ± 3.9 μmol/l to 11.5 ± 2.8 μmol/l; P < 0.01). Flow-mediated dilation also improved significantly, from 6.8% ± 2.1% to 8.9% ± 1.7% (P < 0.01).

Conclusion — These results demonstrate that long-term (6-month) folic acid administration significantly declines homocysteine levels and improves arterial endothelial function and has potential implications for the prevention of atherosclerosis in adults with 3 or more traditional risk factors of CAD and hyperhomocysteinaemia.

Key Words:

• coronary artery disease
• risk factor
• homocysteine
• endothelial function
• folic acid