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Effects of Quercetin on Blood Pressure: A Systematic Review and Meta ‐ Analysis of Randomized Controlled Trials

View Article: PubMed Central - PubMed

ABSTRACT

Background: Quercetin, the most abundant dietary flavonol, has antioxidant effects in cardiovascular disease, but the evidence regarding its effects on blood pressure (BP) has not been conclusive. We assessed the impact of quercetin on BP through a systematic review and meta‐analysis of available randomized controlled trials.

Methods and results: We searched PUBMED, Cochrane Library, Scopus, and EMBASE up to January 31, 2015 to identify placebo‐controlled randomized controlled trials investigating the effect of quercetin on BP. Meta‐analysis was performed using either a fixed‐effects or random‐effect model according to I2 statistic. Effect size was expressed as weighted mean difference (WMD) and 95% CI. Overall, the impact of quercetin on BP was reported in 7 trials comprising 9 treatment arms (587 patients). The results of the meta‐analysis showed significant reductions both in systolic BP (WMD: −3.04 mm Hg, 95% CI: −5.75, −0.33, P=0.028) and diastolic BP (WMD: −2.63 mm Hg, 95% CI: −3.26, −2.01, P<0.001) following supplementation with quercetin. When the studies were categorized according to the quercetin dose, there was a significant systolic BP and diastolic BP‐reducing effect in randomized controlled trials with doses ≥500 mg/day (WMD: −4.45 mm Hg, 95% CI: −7.70, −1.21, P=0.007 and −2.98 mm Hg, 95% CI: −3.64, −2.31, P<0.001, respectively), and lack of a significant effect for doses <500 mg/day (WMD: −1.59 mm Hg, 95% CI: −4.44, 1.25, P=0.273 and −0.24 mm Hg, 95% CI: −2.00, 1.52, P=0.788, respectively), but indirect comparison tests failed to significant differences between doses.

Conclusions: The results of the meta‐analysis showed a statistically significant effect of quercetin supplementation in the reduction of BP, possibly limited to, or greater with dosages of >500 mg/day. Further studies are necessary to investigate the clinical relevance of these results and the possibility of quercetin application as an add‐on to antihypertensive therapy.

No MeSH data available.


Meta‐regression bubble plots of the association between mean changes in systolic and diastolic blood pressure values after quercetin supplementation with quercetin dose and duration of supplementation. The size of each circle is inversely proportional to the variance of change.
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jah31607-fig-0005: Meta‐regression bubble plots of the association between mean changes in systolic and diastolic blood pressure values after quercetin supplementation with quercetin dose and duration of supplementation. The size of each circle is inversely proportional to the variance of change.

Mentions: Potential associations between the antihypertensive effects of quercetin with dose and duration of supplementation were evaluated using meta‐regression analysis. SBP‐lowering effect of quercetin was associated with duration of supplementation (slope: −0.92; 95% CI: −1.52, −0.32; P=0.003) but not the administered dose (slope: −0.003; 95% CI: −0.01, 0.07; P=0.548). With respect to DBP, there was a dose–response association (slope: −0.07; 95% CI: −0.01, −0.002; P=0.005) but the observed effect size was independent of supplementation duration (slope: −0.22; 95% CI: −0.62, 0.18; P=0.276) (Figure 5). Using a covariance matrix analysis of regression coefficients, the covariance of treatment dose and duration was 0 for SBP analysis and −0.0001 for DBP analysis.


Effects of Quercetin on Blood Pressure: A Systematic Review and Meta ‐ Analysis of Randomized Controlled Trials
Meta‐regression bubble plots of the association between mean changes in systolic and diastolic blood pressure values after quercetin supplementation with quercetin dose and duration of supplementation. The size of each circle is inversely proportional to the variance of change.
© Copyright Policy - creativeCommonsBy-nc
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5015358&req=5

jah31607-fig-0005: Meta‐regression bubble plots of the association between mean changes in systolic and diastolic blood pressure values after quercetin supplementation with quercetin dose and duration of supplementation. The size of each circle is inversely proportional to the variance of change.
Mentions: Potential associations between the antihypertensive effects of quercetin with dose and duration of supplementation were evaluated using meta‐regression analysis. SBP‐lowering effect of quercetin was associated with duration of supplementation (slope: −0.92; 95% CI: −1.52, −0.32; P=0.003) but not the administered dose (slope: −0.003; 95% CI: −0.01, 0.07; P=0.548). With respect to DBP, there was a dose–response association (slope: −0.07; 95% CI: −0.01, −0.002; P=0.005) but the observed effect size was independent of supplementation duration (slope: −0.22; 95% CI: −0.62, 0.18; P=0.276) (Figure 5). Using a covariance matrix analysis of regression coefficients, the covariance of treatment dose and duration was 0 for SBP analysis and −0.0001 for DBP analysis.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Quercetin, the most abundant dietary flavonol, has antioxidant effects in cardiovascular disease, but the evidence regarding its effects on blood pressure (BP) has not been conclusive. We assessed the impact of quercetin on BP through a systematic review and meta‐analysis of available randomized controlled trials.

Methods and results: We searched PUBMED, Cochrane Library, Scopus, and EMBASE up to January 31, 2015 to identify placebo‐controlled randomized controlled trials investigating the effect of quercetin on BP. Meta‐analysis was performed using either a fixed‐effects or random‐effect model according to I2 statistic. Effect size was expressed as weighted mean difference (WMD) and 95% CI. Overall, the impact of quercetin on BP was reported in 7 trials comprising 9 treatment arms (587 patients). The results of the meta‐analysis showed significant reductions both in systolic BP (WMD: −3.04 mm Hg, 95% CI: −5.75, −0.33, P=0.028) and diastolic BP (WMD: −2.63 mm Hg, 95% CI: −3.26, −2.01, P<0.001) following supplementation with quercetin. When the studies were categorized according to the quercetin dose, there was a significant systolic BP and diastolic BP‐reducing effect in randomized controlled trials with doses ≥500 mg/day (WMD: −4.45 mm Hg, 95% CI: −7.70, −1.21, P=0.007 and −2.98 mm Hg, 95% CI: −3.64, −2.31, P<0.001, respectively), and lack of a significant effect for doses <500 mg/day (WMD: −1.59 mm Hg, 95% CI: −4.44, 1.25, P=0.273 and −0.24 mm Hg, 95% CI: −2.00, 1.52, P=0.788, respectively), but indirect comparison tests failed to significant differences between doses.

Conclusions: The results of the meta‐analysis showed a statistically significant effect of quercetin supplementation in the reduction of BP, possibly limited to, or greater with dosages of >500 mg/day. Further studies are necessary to investigate the clinical relevance of these results and the possibility of quercetin application as an add‐on to antihypertensive therapy.

No MeSH data available.