Study on the Effects of Epicatechin and Quercetin Supplementation on Vascular Function and Blood Pressure (FLAVO)

Hypertension Clinical Trial

Official title:

Study on the Effects of Epicatechin and Quercetin Supplementation on Vascular Function and Blood Pressure in Untreated (Pre)Hypertensive Subjects

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01691404
• Other study ID #: NL4077208112
• Status: Completed
• Phase: N/A
• First received: September 12, 2012
• Last updated: April 22, 2013
• Start date: September 2012
• Est. completion date: March 2013

Study information

• Verified date: November 2012
• Source: Wageningen University
• Contact: n/a
• Is FDA regulated: No
• Health authority: Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)Netherlands: Medical Ethics Review Committee (METC)
• Study type: Interventional

Clinical Trial Summary

Flavonoid-rich foods such as tea and cocoa have been identified as having a blood pressure-lowering effect. Part of this effect is thought to be due to the flavonoid content of these foods although it is currently unknown which flavonoids play a role. Epicatechin is one the major flavonoids in cocoa while quercetin is largely found in tea.

During this study the investigators plan to investigate the effects of pure epicatechin and quercetin supplementation on vascular function and blood pressure in untreated (prehypertensive) subjects by way of a three-armed double-blind crossover intervention. Participants will sequentially consume supplements containing quercetin, epicatechin or placebo for a period of 4 weeks. Before and after this 4 week period, measurements of vascular function and blood pressure will be taken.

The investigators hypothesize that the supplementation of epicatechin and quercetin will improve vascular function and blood pressure.

Description:

By means of a three-armed double-blind crossover intervention, the effects of pure flavonoid supplementation will be investigated. The products under investigation will be epicatechin and quercetin-3-glucoside. Subjects will be asked to consume either 160mg of quercetin-3-glucoside, 100mg of epicatechin or a placebo capsule for a period of 4 weeks. Measurements of vascular function and blood pressure will be taken before and after each 4-week intervention period. A 4-week washout period will be planned between each intervention.

Measurements of vascular function will include flow-mediated dilation, pulse wave analysis, pulse wave velocity and vasomotion as well as biomarkers of inflammation and vascular function.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 38
• Est. completion date: March 2013
• Est. primary completion date: March 2013
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 30 Years to 80 Years

Eligibility

Inclusion Criteria:

• Systolic Blood Pressure between 125 and 160 mmHg

• Age between 30 and 80 years

• BMI > 20 and = 40

• No reported current or previous metabolic diseases

• No history of cardiovascular diseases

• No history of renal, liver or thyroid diseases

• No history of gastrointestinal diseases

• No diabetes mellitus

• Fasting laboratory parameters within normal range: complete blood count (RBC, WBC, PLT, HB, HT), renal function (serum creatinine, urea), liver function (ALAT, ASAT, ?-GT), and serum glucose.

Exclusion Criteria:

• Body mass index > 40 and =20

• Secondary hypertension

• Weight loss or weight gain of 5 kg or more during the last 2 months

• Usage of non-steroidal anti-inflammatory drugs (acetylsalicylic acid, ibuprofen, naproxen) and not able or willing to stop taking them from at least 4 weeks prior to the study

• Usage of cholesterol-lowering medication

• Daily usage of corticosteroids

• Medical treatment that may affect blood pressure and not able (or willing) to stop

• Taking nutritional supplements and unwilling to discontinue

• Lactating, pregnant or intention to become pregnant during study

• Reported dietary habits, medically prescribed diet, slimming diet

• Reported average alcohol consumption > 2 glasses/d (men) or >1 glass/d (women)

• Problems with consuming the supplements or following the study guidelines

• Unwilling to undergo home or office blood pressure measurements

• Recent blood donation i.e. 1 month (male subjects) or 2 months (female subjects) prior to the study and planned donation during the study period

• Reported intense sporting activities > 10 h/w

• Not agreeing to be informed about unexpected and medically relevant personal test-results, or not agreeing that their general practitioner will be informed about these results

• Participation in another biomedical trial less than 2 months before the start of the study or at the same time

• No signed informed consent form

• Clinical disorders that could interfere with the intervention

• Unable to comply with the study procedure (e.g. holidays, urine collection, blood sampling)

• Smokers

• Difficulty imaging brachial artery by ultrasonography

Study Design

Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Endothelial Dysfunction
• Hypertension

Intervention

Dietary Supplement:
• Epicatechin
Subjects will be asked to consume supplements containing 100mg of epicatechin daily
• Quercetin
Subjects will be asked to consume 160mg of quercetin-3-glucoside daily
• Placebo
Subjects will be asked to consume capsules containing placebo (cellulose) daily

Locations

Country	Name	City	State
Netherlands	Wageningen University	Wageningen

Sponsors (2)

Lead Sponsor	Collaborator
Wageningen University	Top Institute Food and Nutrition

Country where clinical trial is conducted

Netherlands, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in Endothelium-dependent flow-mediated dilation as a result of epicatechin and quercetin-3-glucoside supplementation	Change in arterial diameter as a result of 5 minute arterial occlusion (200mmHg). Arterial diameter will be measured by means of ultrasonography.	Baseline and every 4 weeks thereafter (weeks 4, 8, 12, 16 and 20)	No
Secondary	Change in blood pressure as a result of epicatechin and quercetin-3-glucoside supplementation	Office BP (Dinamap, 4 consecutive measurements with 2-min intervals)and 24-hour ABPM (Spacelab; 1x24h)	Baseline and every 4 weeks thereafter (weeks 4, 8, 12, 16 and 20)	No
Secondary	Change in pulse wave velocity as a result of epicatechin and quercetin supplementation	Measured using a SphygmoCor device at baseline and the end of each intervention	Baseline and every 4 weeks thereafter (weeks 4, 8, 12, 16 and 20)	No
Secondary	Change in vasomotion as a result of epicatechin and quercetin supplementation	Measured using a PeriFlux 5001 device at baseline and the end of each intervention.	Baseline and every 4 weeks thereafter (weeks 4, 8, 12, 16 and 20)	No
Secondary	Changes in biomarkers of endothelial function as a result of epicatechin and quercetin supplementation	Plasma analysis of endothelin-1, ADMA, MCP-1, sVCAM-1, sICAM-1, sE-selectin, sTM, CRP, SAA, IL-6, IL-8, TNF-a, vWF, nitric oxide	Baseline and every 4 weeks thereafter (weeks 4, 8, 12, 16 and 20)	No
Secondary	Changes in peripheral blood mononuclear cell gene expression of markers of inflammation as a result of epicatechin and quercetin supplementation	PBMC gene expression of markers of inflammation	Baseline and every 4 weeks thereafter (weeks 4, 8, 12, 16 and 20)	No
Secondary	Change in cardiovascular parameters in plasma as a result of epicatechin and quercetin supplementation	Total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, insulin and glucose	Baseline and every 4 weeks thereafter (weeks 4, 8, 12, 16 and 20)	No
Secondary	Changes in pulse wave analysis as a result of epicatechin and quercetin supplementation	Measured using a SphygmoCor device at baseline and the end of each intervention	Baseline and every 4 weeks thereafter (weeks 4, 8, 12, 16 and 20)	No
Secondary	Adverse events	During the study subjects will be asked to maintain a diary in which they can report any adverse events they may have a result of the supplements. Diaries will be checked every 2 weeks. Study subjects will also be asked to contact the research team if they experience repeated adverse events.	Baseline and every 2 weeks thereafter (weeks 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20)	Yes

External Links

•   Website for the study (in dutch)
•   Website of Division of Human Nutrition, Wageningen University, The Netherlands