Long-term improvement in homocysteine levels and arterial endothelial function after 1-year folic acid supplementation.
OBJECTIVE
Hyperhomocysteinemia, a risk factor for atherosclerosis, is associated with endothelial dysfunction that can be improved with short-term folic acid supplementation. The current study aimed to assess whether folic acid supplementation could produce longer-term improvements in homocysteine levels and arterial endothelial function.


METHODS
Twenty-nine healthy adults with hyperhomocysteinemia were selected from 89 volunteers enrolled in a community-based atherosclerosis screening project. All subjects were given folic acid (10 mg/d) for 1 year. Fasting plasma homocysteine levels were measured by high-performance liquid chromatography. Arterial endothelial function was measured as flow-mediated dilation of the brachial artery using high-resolution B-mode ultrasound.


RESULTS
Folic acid supplementation for 1 year was associated with a significant increase in mean (+/-SD) plasma folate levels (24 +/- 5 nmol/L to 40 +/- 5 nmol/L; P < 0.001) and a significant decline in homocysteine levels (9.0 +/- 1.7 micromol/L to 7.9 +/- 2.0 micromol/L; P < 0.001). Flow-mediated dilation also improved significantly, from 7.4% +/- 2.0% to 8.9% +/- 1.5% (P <0.0001), but there was no change in nitroglycerin-induced (endothelium-independent) responses.


CONCLUSIONS
These results demonstrate that long-term folic acid improves arterial endothelial function and has potential implications for the prevention of atherosclerosis in adults with hyperhomocysteinemia.
Woo
Kam S
KS
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong.
Chook
Ping
P
Chan
Lindy L T
LL
Cheung
Alice S P
AS
Fung
Wing H
WH
Qiao
M u
Mu
Lolin
Yvette I
YI
Thomas
G N
GN
Sanderson
John E
JE
Metreweli
Con
C
Celermajer
David S
DS
D000328:Adult; D000368:Aged; D001161:Arteriosclerosis / Q000517:prevention & control*; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000187:drug effects*; D005260:Female; D005492:Folic Acid / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000188:drug therapy*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D014463:Ultrasonography; D014664:Vasodilation / Q000187:drug effects
D005492:Folic Acid