Flow Mediated Dilation in Response to Black Tea

Vascular Function Clinical Trial

— T  

Official title:

Flow Mediated Dilation in Response to Consumption of Black Tea Versus Artificial Tea, in Non-tea Drinking Hypertensive Subjects.

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02273323
• Other study ID #: REF-BEV-1376
• Status: Completed
• Phase: N/A
• First received: October 21, 2014
• Last updated: November 17, 2015
• Start date: October 2014
• Est. completion date: October 2015

Study information

• Verified date: November 2015
• Source: Unilever R&D
• Contact: n/a
• Is FDA regulated: No
• Health authority: United Kingdom: National Health Service
• Study type: Interventional

Clinical Trial Summary

Research indicate that people who regularly drink tea have a reduced risk of stroke or heart disease. In a number of studies in which people that normally do not drink showed that their blood vessels function improved when the drunk tea. The current study tests whether a specific black tea improves vessel function in non-tea drinking hypertensive subjects.

Description:

Epidemiological studies indicate that regular consumption of three cups of black tea per day reduces the risk of stroke or myocardial infarction. In a number of previous nutrition intervention studies tea has been shown to improve vascular function as assessed by Flow Mediated Dilation in various populations. The current confirmatory study tests a specific black tea against a placebo in a population of in non-tea drinking hypertensive subjects.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 30
• Est. completion date: October 2015
• Est. primary completion date: October 2015
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 65 Years

Eligibility

Inclusion Criteria:

• Males and post menopausal (> 1 year) females, not on hormone replacement therapy

• Aged >18 and < 65 years

• Body mass index (BMI) of >=18.0 and =<35.0 kg/m2

• Hypertension as previously diagnosed by primary care or hospital physician.

• If untreated, office BP between 140/90 mmHg and 160/100 mmHg on screening

• If treated, a controlled blood pressure (<160/100) on stable medication for at least 4 weeks

Exclusion Criteria:

• Tea drinkers: having typically consumed > 1 cup of black tea per week.

• 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 other than hypertension

• Clinically significant arrhythmia

• Diabetes mellitus

• Chronic Kidney Disease > stage 2

• 10-year cardiovascular risk equivalent to 20% or greater using the QRisk2 calculator

• Abnormality of laboratory blood tests considered clinically significant

• Any other significant intercurrent condition/disease

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)

Related Conditions & MeSH terms

• Vascular Function

Intervention

Other:
• Tea
Single dose of black tea infusion containing approximately 400 mg flavonoids (expressed as gallic acid equivalents) with added sugar.
• Placebo
Placebo: tea flavour, colouring and sugar

Locations

Country	Name	City	State
United Kingdom	Dept Clinical Pharmacology/CRF, St Thomas Hospital	London

Sponsors (2)

Lead Sponsor	Collaborator
Unilever R&D	King's College London

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Flow mediated dilation	Change in flow mediated dilation from baseline	before and 2 hours after test product intake	No
Secondary	endothelium-independent vasodilation	Endothelium-independent dilation after glyceryl trinitrate	2.5 hours after test product intake	No
Secondary	Seated blood pressure	Seated blood pressure measurement (both systolic and diastolic)	55 minutes before (baseline) and 90 minutes after and 175 minutes after test product intake	No
Secondary	Supine blood pressure	Supine blood pressure measurement (both systolic and diastolic)	35 minutes before (baseline) and 110 minutes after test product intake	No