Background:
This systematic review and meta-analysis of randomized controlled trials (RCTs) were
performed to determine the effect of quercetin administration on blood pressures and endothelial function among
patients with metabolic syndrome (MetS) and related disorders.
Methods:
We searched systematically online databases including Cochrane Library, EMBASE, MEDLINE, and
Web of Science to identify the relevant RCTs until December 2018. Q-test and I2 statistics were applied to assess
heterogeneity among the included studies. Data were pooled using a random-effects model and weighted mean
difference (WMD) was considered as the overall effect size.
Results:
Out of 284 citations, 8 RCTs were included in the meta-analysis. We found a significant reduction in
systolic blood pressure (SBP) (WMD: -1.69; 95% CI: -3.22, -0.17) following the intake of quercetin supplements.
However, quercetin supplementation did not significantly affect diastolic blood pressure (DBP) (WMD: -3.14;
95% CI: -8.24, 1.95), vascular cell adhesion molecule 1 (VCAM-1) (WMD: -24.49; 95% CI: -53.74, 4.77) and
intercellular adhesion molecule 1 (ICAM-1) (WMD: -5.78; 95% CI: -12.93, 1.38).
Conclusions:
In summary, the current meta-analysis demonstrated that quercetin supplementation significantly
reduced SBP, yet did not affect DBP, VCAM-1 and ICAM-1 among patients with MetS and related disorders.