The effect of oral L-arginine supplementation on asymmetric dimethylarginine levels: A systematic review and meta-analysis of randomized clinical trials

Abstract

AimsCardiovascular disease (CVD) is the main cause of mortality around the world. Asymmetric dimethylarginine (ADMA), as an inhibitor of nitric oxide synthase and cardiovascular risk factor, can potentially be increased by L-Arginine intake. The aim of the present meta-analysis is to determine the effect of oral L-Arginine supplementation on ADMA. MethodsPubMed, Medline, Scopus, Cochrane Library and Web of Science databases were searched for the relevant randomized clinical trials up to Oct 2018. WMD and 95% CI was reported for the ADMA changes. Random-effect model was conducted for heterogeneous data. Sensitivity and subgroup analysis was performed in order to find the source of heterogeneity. Egger’s and Begg’s test and funnel plots was performed to identify existing publication bias. Jadad scale was used for rating included trials. ResultsA total of 6 trials met eligibility criteria for inclusion. Results from these trials found that there was no significant effect of L-Arginine supplementation on ADMA levels using random-effect analysis (WMD = −0.04 mg/dl; 95% CI: −0.39–0.31; P = 0.83, I2 = 99.0%; P = <0.001) as well as using the subgroup analysis by mean age, intervention dosage and duration. The effect of sensitivity analysis was not significant. ConclusionThis meta-analysis of randomized clinical trials showed no significant effect of L-Arginine supplementation on ADMA levels.