Evidence map›Paper›PMID 26328470›Full record

Trial reportThe British journal of nutrition2015

Effects of a quercetin-rich onion skin extract on 24 h ambulatory blood pressure and endothelial function in overweight-to-obese patients with (pre-)hypertension: a randomised double-blinded placebo-controlled cross-over trial.

Verena Brüll, Constanze Burak, Birgit Stoffel-Wagner, Siegfried Wolffram, Georg Nickenig, Cornelius Müller, Peter Langguth, Birgit Alteheld, Rolf Fimmers, Stefanie Naaf and 3 more

Open access · hybridAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in The British journal of nutrition, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 95 papers, 7 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
95citing papers in PubMed, 7 pooled it
6.4field-weighted citation impact, top 2% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

95 citing papers in PubMed, 7 syntheses or guidelines pooled it, 228 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. Pooled it
  5. Pooled it
  6. Pooled it
  7. Pooled it
  8. Trial
  9. Trial
  10. Trial
  11. Trial
  12. Trial
  13. Trial
  14. Trial
  15. Trial
  16. Review
  17. Review
  18. Review
  19. Article
  20. Article

35 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

13 authors at 5 institutions in 1 country.

Verena Brüll1Department of Nutrition and Food Sciences,Nutritional Physiology,University of Bonn,53115 Bonn,Germany.
Constanze Burak1Department of Nutrition and Food Sciences,Nutritional Physiology,University of Bonn,53115 Bonn,Germany.
Birgit Stoffel-Wagner2Institute of Clinical Chemistry and Clinical Pharmacology,University Hospital Bonn,53127 Bonn,Germany.
Siegfried Wolffram3Institute of Animal Nutrition and Physiology,Christian-Albrechts-University Kiel,24118 Kiel,Germany.
Georg Nickenig4Department of Cardiology,Angiology and Pneumology,University Hospital Bonn,53127 Bonn,Germany.
Cornelius Müller4Department of Cardiology,Angiology and Pneumology,University Hospital Bonn,53127 Bonn,Germany.
Peter Langguth5Department of Biopharmaceutics and Pharmaceutical Technology,Institute of Pharmacy and Biochemistry,Johannes Gutenberg University Mainz,55099 Mainz,Germany.
Birgit Alteheld1Department of Nutrition and Food Sciences,Nutritional Physiology,University of Bonn,53115 Bonn,Germany.
Rolf Fimmers6Institute of Medical Biometry,Informatics and Epidemiology,University Hospital Bonn,53127 Bonn,Germany.
Stefanie Naaf7Institut Prof. Dr. Georg Kurz GmbH,50933 Köln,Germany.
Benno F Zimmermann7Institut Prof. Dr. Georg Kurz GmbH,50933 Köln,Germany.
Peter Stehle1Department of Nutrition and Food Sciences,Nutritional Physiology,University of Bonn,53115 Bonn,Germany.
Sarah Egert1Department of Nutrition and Food Sciences,Nutritional Physiology,University of Bonn,53115 Bonn,Germany.
University of Bonn · DEUniversity Hospital Bonn · DEInstitut Kurz · DEJohannes Gutenberg University Mainz · DEKiel University · DE

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The polyphenol quercetin may prevent CVD due to its antihypertensive and vasorelaxant properties. We investigated the effects of quercetin after regular intake on blood pressure (BP) in overweight-to-obese patients with pre-hypertension and stage I hypertension. In addition, the potential mechanisms responsible for the hypothesised effect of quercetin on BP were explored. Subjects (n 70) were randomised to receive 162 mg/d quercetin from onion skin extract powder or placebo in a double-blinded, placebo-controlled cross-over trial with 6-week treatment periods separated by a 6-week washout period. Before and after the intervention, ambulatory blood pressure (ABP) and office BP were measured; urine and blood samples were collected; and endothelial function was measured by EndoPAT technology. In the total group, quercetin did not significantly affect 24 h ABP parameters and office BP. In the subgroup of hypertensives, quercetin decreased 24 h systolic BP by -3·6 mmHg (P=0·022) when compared with placebo (mean treatment difference, -3·9 mmHg; P=0·049). In addition, quercetin significantly decreased day-time and night-time systolic BP in hypertensives, but without a significant effect in inter-group comparison. In the total group and also in the subgroup of hypertensives, vasoactive biomarkers including endothelin-1, soluble endothelial-derived adhesion molecules, asymmetric dimethylarginine, angiotensin-converting enzyme activity, endothelial function, parameters of oxidation, inflammation, lipid and glucose metabolism were not affected by quercetin. In conclusion, supplementation with 162 mg/d quercetin from onion skin extract lowers ABP in patients with hypertension, suggesting a cardioprotective effect of quercetin. The mechanisms responsible for the BP-lowering effect remain unclear.

Indexed as

AdultAgedAntihypertensive AgentsBiomarkersBlood PressureBlood Pressure Monitoring, AmbulatoryBody CompositionBody Mass IndexBody WeightCholesterolC-Reactive ProteinCross-Over StudiesDietary SupplementsDouble-Blind MethodEndothelium, VascularEnergy IntakeAntihypertensive AgentsBiomarkersCholesterolC-Reactive ProteinInsulinPlant ExtractsQuercetinTriglyceridesABP ambulatory blood pressureACE angiotensin-converting enzymeADMA asymmetric dimethylarginineBlood pressureBP blood pressureCardiovascular diseasesDBP diastolic blood pressureEndothelial functionHypertensionIsoP isoprostanesMAP mean arterial pressureoxLDL oxidised LDLPAT peripheral arterial tonometryQuercetinRHI reactive hyperaemia indexSBP systolic blood pressuresICAM-1 soluble intercellular adhesion molecule 1sVCAM-1 soluble vascular cell adhesion molecule 1

Identifiers

PMID26328470
PMCPMC4594049
OpenAlexW2100337344

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.