L-arginine supplementation prolongs exercise capacity in congestive heart failure.
BACKGROUND
In congestive heart failure (CHF), endothelial dysfunction may contribute to impairment of exercise induced vasodilatation and decreased exercise capacity. We hypothesised that administration of L-arginine, a precursor of nitric oxide (NO) and postulated antioxidant, may improve endothelium-dependent vasodilatation and exercise capacity and also exert antioxidant activity.


OBJECTIVE
To investigate the effect of oral supplementation with L-arginine on exercise capacity and markers of oxidative stress in patients with mild to moderate CHF.


METHODS
The study had a randomised double-blind cross-over design. Twenty one patients with stable NYHA II-III CHF underwent three exercise tests: initially, after oral administration of L-arginine (9 g/day for 7 days) or placebo. Blood was sampled prior to each test for plasma lipid peroxides, reduced sulphydryl groups and leukocyte oxygen free radical production.


RESULTS
We found a higher prolongation of exercise duration time after L-arginine than after placebo (99+/-106 vs 70+/-99 s, p<0.05). There were no significant differences in markers of free radical activity.


CONCLUSIONS
In patients with chronic stable CHF, oral supplementation with L-arginine prolongs exercise duration which may be due to NO-induced peripheral vasodilatation. The antioxidant properties of L-arginine have not been confirmed in this ex vivo study.
Bednarz
Bronisław
B
Department of Cardiology, Postgranduate Medical School, Grochowski Hospital, Warsaw, Poland.
Jaxa-Chamiec
Tomasz
T
Gebalska
Jadwiga
J
Herbaczyńska-Cedro
Krystyna
K
Ceremuzyński
Leszek
L
D000368:Aged; D001120:Arginine / Q000494:pharmacology* / Q000627:therapeutic use; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000187:drug effects*; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000494:pharmacology* / Q000627:therapeutic use
D014665:Vasodilator Agents; D001120:Arginine