The effects of resveratrol on lipid profiles and liver enzymes in patients with metabolic syndrome and related disorders: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: There are current trials investigating the effect of resveratrol supplementation on lipid profiles and liver enzymes among patients with metabolic syndrome (MetS) and related disorders; however, their findings are controversial. This systematic review and meta-analysis were aimed to determine the effects of resveratrol supplementation on lipid profiles and liver enzymes among patients with MetS and related disorders. METHODS: We performed a comprehensive search of the following online databases up to November 2018: Cochrane Library, PubMed, Embase, and Web of Science. The relevant articles were assessed for quality of studies using the Cochrane risk of bias tool. RESULTS: Out of 2459 citations, 31 articles were appropriate for including to the current meta-analysis. The pooled results indicated that resveratrol use significantly decreased total cholesterol [weighted mean difference (WMD) = - 7.65 mg/dL; 95% CI, - 12.93, - 2.37; P < 0.01; I(2): 83.4%] and increased gamma-glutamyl transferase (GGT) concentrations (WMD = 1.76 U/l; 95% CI, 0.58, 2.94; P < 0.01; I(2): 20.1%). We found no significant effect of resveratrol supplementation on triglycerides (WMD = - 5.84 mg/dL; 95% CI, - 12.68, 1.00; P = 0.09; I(2): 66.8%), LDL- (WMD = -2.90 mg/dL; 95% CI, - 10.88, 5.09; P = 0.47; I(2): 96.0%), HDL-cholesterol (WMD = 0.49 mg/dL; 95% CI, - 0.80, 1.78; P = 0.45; I(2): 74.0%), alanine aminotransferase (ALT) (WMD = -0.14 U/l; 95% CI, - 3.69, 3.41; P = 0.93; I(2): 79.6%), and aspartate aminotransferase (AST) (WMD = -0.34 U/l; 95% CI, - 2.94, 2.27; P = 0.80; I(2): 88.0%) concentrations. CONCLUSIONS: This meta-analysis demonstrated that resveratrol supplementation among patients with MetS and related disorders significantly reduced total cholesterol and increased GGT concentrations, but did not affect triglycerides, LDL-, HDL-cholesterol, ALT, and AST concentrations. This data suggests that resveratrol may have a potential cardio-protective effect in patients with MetS and related disorders.