Am J Clin Nutr: L-arginine supplementation improves exercise capacity after a heart transplant.
|Article Type:||Brief article|
Exercise (Health aspects)
Blood circulation disorders (Risk factors)
Blood circulation disorders (Research)
Heart (Complications and side effects)
Di Marco, P.
|Publication:||Name: Alternative Medicine Review Publisher: Thorne Research Inc. Audience: Academic; Professional Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2010 Thorne Research Inc. ISSN: 1089-5159|
|Issue:||Date: June, 2010 Source Volume: 15 Source Issue: 2|
|Topic:||Event Code: 310 Science & research|
|Geographic:||Geographic Scope: United States Geographic Code: 1USA United States|
BACKGROUND: Endothelial dysfunction is associated with the
decreased exercise capacity observed in heart-transplant (HTx)
recipients. L-arginine supplementation (LAS) stimulates the nitric oxide
(NO) pathway and restores endothelial function. OBJECTIVE: We compared
exercise capacity in healthy subjects and HTx patients and investigated
whether chronic LAS might improve exercise capacity and NO/endothelin
balance after an HTx. DESIGN: Clinical, echocardiographic, and exercise
characteristics were measured in 11 control subjects and 22 HTx
recipients. In a prospective, double-blind study, the 22 HTx recipients
performed a 6-min exercise [6-min-walk test (6MWT)] and a maximal
bicycle exercise test before and after a 6-wk period of placebo intake
or LAS. Endothelial function was measured by analyzing blood NO
metabolites, endothelin, and the resulting NO/endothelin balance.
RESULTS: Exercise capacity decreased after transplantation. Unlike with
the placebo intake, a 6-wk LAS improved quality of life in HTx
recipients (mean [+ or -] SEM Minnesota Score: from 15.3 [+ or -] 1.3 to
10.6 [+ or -] 1.1; p< 0.001) and their submaximal exercise capacity.
The distance walked during the 6MWT increased (from 525 [+ o r -] 20 to
580 [+ or -] 20 m; p=0.002), and the ventilatory threshold during the
incremental test was delayed by 1.2 min (p=0.01). Central factors such
as resting stroke volume, systolic pulmonary arterial pressure, cardiac
systolodiastolic functions, and heart-rate reserve were not modified,
but LAS significantly increased the NO:endothelin ratio (from 2.49 [+ or
-] 0.38 to 3.31 [+ or -] 0.39; p=0.03). CONCLUSION: Oral LAS may be a
useful adjuvant therapeutic to improve quality of life and exercise
tolerance in HTx recipients.
2010 Mar 3. [Epub ahead of print]
|Gale Copyright:||Copyright 2010 Gale, Cengage Learning. All rights reserved.|