Abstract

Several studies have examined the effect of oral L-Arginine supplementation on lipid profiles and inflammatory markers. However, findings are inconsistent in this regard. Therefore, the aim of this study is to summarize and examine the effect of L-Arginine supplementation on lipid profiles and inflammatory markers in published randomized controlled trials (RCTs). We searched PubMed/Medline, SCOPUS, ISI web of science, and Google Scholar up to May 2019. The weighted mean difference (WMD) and 95 confidence interval (CI) as mean changes of lipid profiles and inflammatory markers between L-Arginine supplementation and control groups were calculated using a random effect model. Subgroup analysis was used to find potential sources of heterogeneity among studies. A total of 6282 RCTs were found, of which 17 were included in the present study. A meta-analysis of 13 trials which reported the data on triglyceride (TG) revealed a borderline significant effect of the L-Arginine on TG values (WMD = -6.03 mg/di; 95 CI: -12,- 0.07, P = 0.04). Compared with the Placebo groups, there was no significant effect on low-density lipoprotein cholesterol (LDL-c), total cholesterol (TC), and high-density lipoprotein cholesterol (HDL-c) after L-Arginine treatment. According to the results of the present systematic review and meta-analysis, L-Arginine does not significantly affect CRP and TNF alpha indices. This review of systematic review suggests that although L-Arginine supplementation significantly reduces TG levels, other lipid profiles and inflammatory indices might not be influential. Therefore, further RCTs are recommended to assess the effect of oral L-Arginine intake on other lipid and inflammation indices.