Clinical trial NCT02273323: Flow Mediated Dilation in Response to Black Tea
Official title: Flow Mediated Dilation in Response to Consumption of Black Tea Versus Artificial Tea, in Non-tea Drinking Hypertensive Subjects.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Vascular Function
Keywords: Flow mediated dilation
tea
blood pressure
Lead sponsor: Unilever R&D
Sponsor class: INDUSTRY
Collaborators: name: King's College London
First posted: 2014-10-23
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER

Brief 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.

Detailed 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.

Eligibility criteria: 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

Primary outcomes:
measure: Flow Mediated Dilation
timeFrame: Before and 2 hours after test product intake
Secondary outcomes:
measure: Endothelium-independent Vasodilation
timeFrame: 2.5 hours after test product intake
measure: Systolic Blood Pressure Supine
timeFrame: Before and 110 minutes after test product intake
measure: Diastolic Blood Pressure Supine
timeFrame: Before and 110 minutes after test product intake
measure: Systolic Blood Pressure Sitting
timeFrame: Before and 90 minutes after test product intake
measure: Diastolic Blood Pressure Sitting
timeFrame: Before and 90 minutes after test product intake
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: Dept Clinical Pharmacology/CRF, St Thomas Hospital
Study officials:
affiliation: Dept Clinical Pharmacology/CRF, St Thomas Hospital, London UK
name: Phillip Chowienczyk, Professor
role: PRINCIPAL_INVESTIGATOR
References: