Effect of Tea on Endothelial Function and Ischaemia-reperfusion Injury

This study has been completed.
Sponsor:
Collaborator:
Unilever R&D
Information provided by (Responsible Party):
Radboud University
ClinicalTrials.gov Identifier:
NCT01660516
First received: August 6, 2012
Last updated: February 1, 2013
Last verified: July 2012
  Purpose

Tea consumption may impact upon the decrease in endothelial function after IR-injury. However, no previous study directly examined the potential of tea to impact upon the change in endothelial function after IR-injury.

The investigators hypothesize that tea consumption counteracts endothelial damage in response to ischaemia reperfusion injury in healthy humans.


Condition
Ischaemia Reperfusion Injury

Study Type: Observational
Study Design: Observational Model: Case-Crossover
Time Perspective: Cross-Sectional
Official Title: Effect of Black Tea Consumption on Endothelial Function and Ischaemia-reperfusion Injury in Humans

Resource links provided by NLM:


Further study details as provided by Radboud University:

Primary Outcome Measures:
  • Change in Endothelial Function after ischaemia reperfusion injury [ Time Frame: three weeks ] [ Designated as safety issue: No ]
    Change in endothelial function (measured with flow mediated dilation) after ischaemia reperfusion injury (induced by 20 minutes ischemia and 20 min reperfusion) with and without precedence of tea consumption


Secondary Outcome Measures:
  • Change in baseline flow mediated dilation after water/tea consumption [ Time Frame: three weeks ] [ Designated as safety issue: No ]
    Change in baseline flow mediated dilation after water/tea consumption


Enrollment: 23
Study Start Date: August 2011
Study Completion Date: February 2012
Primary Completion Date: February 2012 (Final data collection date for primary outcome measure)
Groups/Cohorts
Tea
Black tea ingestion

Detailed Description:

Rationale: Occlusion of an artery (causing ischemia) is a frequently reported condition, e.g. myocardial infarction, cerebral infarction or during organ transplantations. The period of ischemia will be followed by reperfusion (possibly after an operation). The ischaemic period as well as the reperfusion are both associated with damage to the tissue, including the endothelium. It is hypothesised that production of oxidative stress and reduced NO bioactivity (through increased reactive oxygen production) during ischaemia and reperfusion is involved in the development of tissue damage to the endothelium. Interventions that can prevent or attenuate endothelial dysfunction in response to ischemia-reperfusion (IR)-injury have a potential clinical relevance to prevent (complications of) cardiovascular disease.

Several studies have examined the effect of tea consumption on the endothelial function. These studies demonstrated a dose-dependent improvement of tea to improve endothelial function in healthy and diseased humans, possibly through the vasoactive effects of flavonoids, which may involve increased nitric oxide bioactivity and inhibition of NADPH oxidase. Based on the ability of flavonoids to decrease (the impact of) oxidative stress, tea consumption may also impact upon the decrease in endothelial function after IR-injury. However, no previous study directly examined the potential of tea to impact upon the change in endothelial function after IR-injury.

Objective: To examine whether tea consumption counteracts endothelial damage in response to ischaemia reperfusion injury in healthy humans.

Main study parameters: Change in endothelial function (measured with flow mediated dilation) after ischaemia reperfusion injury (induced by 20 minutes ischemia and 20 min reperfusion) with and without precedence of tea consumption.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Non-invasive cuff occlusion is used to examine endothelial function (5-minute ischaemia) and produce the stimulus that induces ischaemia-reperfusion injury (20-minute ischaemia). This repeated cuff inflation is non-invasive and not associated with a health risk for the subject. Tea consumption is safe and, most likely, daily routine for most participants. The only difference is that this study will monitor and instruct participants regarding their tea consumption in the week preceding the tests. The volunteers will not benefit directly from participating in this study.

  Eligibility

Ages Eligible for Study:   18 Years to 60 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population

Twenty-one volunteers, aged between 30 and 70 years, were included in our study. All subjects were healthy and free of (a history of) cardiovascular disease or obesity (BMI >30 kg/m2). Individuals were excluded if they reported a chronic or acute disease, including any kind of metabolic abnormality (such as diabetes mellitus) or cardiovascular disease. Habitual smokers (n=3) were instructed to withdraw from smoking on the day of testing. To further avoid confounding factors, the investigators also excluded individuals reporting daily intense sporting activities (>10 h/w), and/or were treated with a diet due to any reason.

Criteria

Inclusion Criteria:

  • Healthy volunteers : age 18-60
  • All subjects: written informed consent

Exclusion Criteria:

  • Smoking
  • History of any cardiovascular disease
  • Hypertension (in supine position: systole >140 mmHg, diastole >90 mmHg)
  • Diabetes Mellitus
  • Hyperlipidaemia (fasting total cholesterol >6.5 mmol/L)
  • Chronic use of medication known to interfere with the cardiovascular system
  • Professional athletes
  • Alcohol consumption >14 units/week
  • BMI >30 kg/m2
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01660516

Locations
Netherlands
Radboud University Nijmegen Medical Centre
Nijmegen, Gelderland, Netherlands, 6525 EX
Sponsors and Collaborators
Radboud University
Unilever R&D
Investigators
Principal Investigator: Dick Thijssen, Dr. Radboud University Medical Centre Nijmegen
Principal Investigator: Maria Hopman, Prof. Dr. Radboud University
  More Information

No publications provided

Responsible Party: Radboud University
ClinicalTrials.gov Identifier: NCT01660516     History of Changes
Other Study ID Numbers: TEA-IRI, Tea-IR-Injury-FMD
Study First Received: August 6, 2012
Last Updated: February 1, 2013
Health Authority: Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)

Keywords provided by Radboud University:
Camellia sinensis
flavonoids
cardiovascular risk
flow mediated dilation

Additional relevant MeSH terms:
Ischemia
Reperfusion Injury
Wounds and Injuries
Pathologic Processes
Vascular Diseases
Cardiovascular Diseases
Postoperative Complications

ClinicalTrials.gov processed this record on July 10, 2014