- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT02328339
Tea and Forearm Blood Flow
Forearm Blood Flow Response to Acute Consumption of Black Tea
Study Overview
Detailed Description
Epidemiological studies indicate that regular consumption of black tea reduces the risk of cardiovascular diseases. Tea consumption can result in improvements in endothelial function of conduit arteries as measured by flow mediated dilation.
Less is known however about its effects in other vascular beds. The study will test the hypothesis that tea affects endothelial function in the muscle microcirculation. This will be done by assessment of forearm blood flow using venous occlusion plethysmography after consumption of black tea against or placebo in a randomised, full cross-over study in 20 healthy middle-aged to elderly subjects
Study Type
Enrollment (Actual)
Phase
- Not Applicable
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- Males and post menopausal (> 1 years) females
- Aged ≥ 45 and ≤ 75 years
- Body mass index (BMI) of ≥ 18.0 and ≤ 35.0 kg/m2
- Judged to be in good health on the basis of medical history, physical examination and routine laboratory tests (total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, glucose, highly sensitive C-reactive protein).
- Normal blood coagulation as assessed by routine lab tests
Exclusion Criteria:
- Strenuous exercise > 2 hours per week. Strenuous exercise is defined as exercise which induces sweating and causes sufficient breathlessness to limit conversation
- Current smoker or has stopped smoking less than 6 months before start of study
- Self reported alcohol intake of > 21 units/week)
- Established cardiovascular disease or clinically significant arrhythmia
- Diabetes mellitus
- Blood pressure > 160/100 mmHg
- Taking medication that might affect endothelial function (as judged by the PI)
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Basic Science
- Allocation: Randomized
- Interventional Model: Crossover Assignment
- Masking: Quadruple
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
---|---|
Experimental: Black tea
Approximately 400 mg total polyphenols in 240 ml hot water (loading dose; 2 hours before the start of measurements; t=0) and 130 mg total polyphenols in 120 ml hot water (maintenance dose just before start of the measurements; t=120 min)
|
Black tea infusion equivalent to approximately 530 mg total polyphenols expressed as gallic acid equivalents
|
Placebo Comparator: Placebo
Caramel colour, maltodextrin and tea flavour in 240 ml hot water (2 hours before the start of measurements; t=0) and 120 ml hot water (maintenance dose just before start of the measurements; t=120 min)
|
Placebo matched to tea with respect to taste and appearance
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
Forearm blood flow response to acetylcholine
Time Frame: During acetylcholine infusion 120-140 min after first tea/placebo intake
|
Does tea ingestion change mean forearm blood flow response to acetylcholine when compared to placebo
|
During acetylcholine infusion 120-140 min after first tea/placebo intake
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
Forearm blood flow response to sodium nitropusside
Time Frame: During sodium nitropusside infusion 170-190 min after first tea/placebo intake
|
Does tea ingestion change mean forearm blood flow response to sodium nitropusside when compared to placebo
|
During sodium nitropusside infusion 170-190 min after first tea/placebo intake
|
Forearm blood flow response to L-NMMA
Time Frame: During L-NMMA infusion 220-240 min after first tea/placebo intake
|
Does tea ingestion change mean forearm blood flow response to L-NG-monomethyl Arginine (L-NMMA) when compared to placebo
|
During L-NMMA infusion 220-240 min after first tea/placebo intake
|
Collaborators and Investigators
Sponsor
Collaborators
Investigators
- Principal Investigator: Sean Roerink, Dr., Radboud university medical center
Publications and helpful links
Study record dates
Study Major Dates
Study Start
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Estimate)
Study Record Updates
Last Update Posted (Estimate)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Other Study ID Numbers
- REF-BEV-1797
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
product manufactured in and exported from the U.S.
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.
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