HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 89/1/77    most recent ajcn.2008.26544v1 Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Bai, Y. Articles by Hui, R. Search for Related Content PubMed PubMed Citation Articles by Bai, Y. Articles by Hui, R. Agricola Articles by Bai, Y. Articles by Hui, R.

Increase in fasting vascular endothelial function after short-term oral L-arginine is effective when baseline flow-mediated dilation is low: a meta-analysis of randomized controlled trials^1,2,3

¹ From the Key Laboratory for Clinical Cardiovascular Genetics & Sino-German Laboratory for Molecular Medicine, Cardiovascular Institute & FuWai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China (YB, TY, KS, JC, and RH); the Hypertension Division, Cardiovascular Institute & FuWai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China (YB and RH); and the National Center for Pharmaceutical Screening, Institute of Materia Medica Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China (LS).

² Supported by grant no. 2006CB503805 from the Ministry of Science and Technology of China (to RH).

³ Address requests for reprints and correspondence to R Hui, Cardiovascular Institute & FuWai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, 167 Beilishilu, Beijing 100037, PR China. E-mail: huirutai{at}gmail.com.

Background: Previous trials suggest that oral L-arginine administration affects endothelial function. However, most of these studies were small, the conclusions were inconsistent, and the precise effects are therefore debatable.

Objective: The objective was to assess the effect of oral L-arginine supplementation on endothelial function, as measured with the use of fasting flow-mediated dilation (FMD).

Design: We conducted a meta-analysis of randomized, placebo-controlled L-arginine supplementation trials that evaluated endothelial function. Trials were identified in PubMed, Cochrane Library, Embase, reviews, and reference lists of relevant papers. The weighted mean difference (WMD) was calculated for net changes in FMD by using random-effect models. Previously defined subgroup analyses and meta-regression analyses were performed to explore the influence of study characteristics.

Results: Thirteen trials were included and evaluated. Because there was only one long-term study, we focused on short-term effects of L-arginine (12 studies, 492 participants). In an overall pooled estimate, L-arginine significantly increased FMD (WMD: 1.98%; 95% CI: 0.47, 3.48; P = 0.01). Meta-regression analysis indicated that the baseline FMD was inversely related to effect size (regression coefficient = –0.55; 95% CI: –1.00, –0.1; P = 0.016). A subgroup analysis suggested that L-arginine supplementation significantly increased FMD when the baseline FMD levels were <7% (WMD: 2.56%; 95% CI: 0.87, 4.25; P = 0.003), but had no effect on FMD when baseline FMD was >7% (WMD: –0.27%; 95% CI: –1.52, 0.97; P = 0.67).

Conclusion: Short-term oral L-arginine is effective at improving the fasting vascular endothelial function when the baseline FMD is low.