L-arginine improves endothelial function and reduces LDL oxidation in patients with stable coronary artery disease.
BACKGROUND
We investigated the effects of oral L-arginine on endothelial function, intravascular oxidative stress, and circulating inflammatory markers in patients with stable coronary artery disease (CAD).


METHODS
Thirty-one stable CAD patients were randomly assigned to oral L-arginine (10 g) or vitamin C (500 mg, an antioxidant, as active control) daily for 4 weeks, with crossover to the alternate therapy after 2 weeks off therapy, in this study. Brachial artery endothelial function studies were performed and serum concentrations of lipids and inflammatory markers were measured at baseline, at the end of each 4-week treatment period and at the 2-week wash-out period. Susceptibility of low-density lipoprotein (LDL) particles to oxidation, a marker of oxidative stress, was determined in 11 patients at random before and after 4-week treatment of oral L-arginine.


RESULTS
We demonstrates that consumption of either L-arginine or vitamin C significantly increased brachial artery flow-mediated dilatation (mean diameter change from baseline of 4.87%, P<0.0001 and of 3.17%, P=0.0003, respectively). Neither oral L-arginine nor vitamin C affected lipid profiles and circulating levels of inflammatory markers. However, in the 11 patients whose LDL susceptibility to oxidation was determined, lag time significantly increased by 27.1% (P=0.045) after consumption of L-arginine for 4 weeks.


CONCLUSIONS
Oral L-arginine supplement improved endothelial function and reduced LDL oxidation in stable CAD patients.
Yin
Wei-Hsian
WH
Division of Cardiology, Cheng-Hsin General Hospital, and Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Chen
Jaw-Wen
JW
Tsai
Chingmin
C
Chiang
Meng-Cheng
MC
Young
Mason Shing
MS
Lin
Shing-Jong
SJ
D000284:Administration, Oral; D001120:Arginine / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000009:adverse effects; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000188:drug therapy* / Q000378:metabolism*; D018592:Cross-Over Studies; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D012449:Safety
D008077:Lipoproteins, LDL; D001120:Arginine; D001205:Ascorbic Acid