Effect of Black Tea on Vascular Function

Not Applicable

Completed

• Conditions: Vascular Function

• Registration Number: NCT01945970
• Lead Sponsor: Unilever R&D

Brief Summary

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 (FMD).

Detailed Description

The current study tests a specific Black tea extract against a placebo in population that has previously show to be sensitive to the effect of black tea on Flow Mediated dilation. A tea extract that has previously been shown to improve FMD is included as the positive control.

Study Timeline

• Study Start: 2013-09
• Study First Submitted: 2013-09-08
• Study First Submitted QC: 2013-09-16
• Study First Posted: 2013-09-19
• Primary Completion: 2013-11
• Study Completion: 2013-12
• Results First Submitted: 2016-12-23
• Results First Submitted QC: 2016-12-23
• Status Verified: 2017-02
• Results First Posted: 2017-02-17
• Last Update Submitted: 2017-02-17
• Last Update Posted: 2017-03-22

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 30

Inclusion Criteria

• Apparently healthy male volunteers with no history of cardiovascular disease
• Having body mass index (BMI) of between 18.0 and 30.0 kg/m2 (inclusive)
• Non-smokers (> 2 years)
• Non-tea drinkers (less or equal 1 cup/week)
• Limited alcohol intake (less or equal 21 units/week)
• Systolic blood pressure less or equal 160 mmHg and/or diastolic blood pressure less or equal 100 mmHg at screening
• Brachial artery can be imaged using ultrasound and at screening FMD value is within the expected range as judged by the PI
• 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).

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Flow Mediated Dilation, Acute-upon-chronic, Black Tea	From before consumption on day 1 to 2 hours post consumption on day 8.	Flow mediated dilation (FMD) measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (Resting stage); * 5 minutes of forearm occlusion at 300±30 mmHg (cuff occlusion stage), just below the elbow 2-5 cm from antecubital crease); * 4 minutes FMD scan, which started immediately after release of occlusion (reactive hyperaemia stage); * When the artery had returned to baseline a second 1 minute scan was taken; * 25 µg sublingual glyceryl trinitrate (GTN) was given to the subject; * 5 minutes GTN scan to assess the endothelium-independent dilation FMD and response to GTN was calculated as maximal percent increase in diameter above baseline (mean value of measures obtained during 1 minute before cuff inflation).

Secondary Outcome Measures

Name	Time	Method
Flow Mediated Dilation, Acute, Black Tea	From before consumption on day 1 to 2 hours post consumption on day 1	Flow mediated dilation (FMD) measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (Resting stage); * 5 minutes of forearm occlusion at 300±30 mmHg (cuff occlusion stage), just below the elbow 2-5 cm from antecubital crease); * 4 minutes FMD scan, which started immediately after release of occlusion (reactive hyperaemia stage); * When the artery had returned to baseline a second 1 minute scan was taken; * 25 µg sublingual glyceryl trinitrate (GTN) was given to the subject; * 5 minutes GTN scan to assess the endothelium-independent dilation FMD and response to GTN was calculated as maximal percent increase in diameter above baseline (mean value of measures obtained during 1 minute before cuff inflation).
Flow Mediated Dilation, Chronic, Black Tea	From before consumption day 1 to before consumption day 8.	Flow mediated dilation (FMD) measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (Resting stage); * 5 minutes of forearm occlusion at 300±30 mmHg (cuff occlusion stage), just below the elbow 2-5 cm from antecubital crease); * 4 minutes FMD scan, which started immediately after release of occlusion (reactive hyperaemia stage); * When the artery had returned to baseline a second 1 minute scan was taken; * 25 µg sublingual glyceryl trinitrate (GTN) was given to the subject; * 5 minutes GTN scan to assess the endothelium-independent dilation FMD and response to GTN was calculated as maximal percent increase in diameter above baseline (mean value of measures obtained during 1 minute before cuff inflation).
Flow Mediated Dilation, Acute-upon-chronic, Positive Control	From before consumption on day 1 to 2 hours post consumption on day 8	Flow mediated dilation (FMD) measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (Resting stage); * 5 minutes of forearm occlusion at 300±30 mmHg (cuff occlusion stage), just below the elbow 2-5 cm from antecubital crease); * 4 minutes FMD scan, which started immediately after release of occlusion (reactive hyperaemia stage); * When the artery had returned to baseline a second 1 minute scan was taken; * 25 µg sublingual glyceryl trinitrate (GTN) was given to the subject; * 5 minutes GTN scan to assess the endothelium-independent dilation FMD and response to GTN was calculated as maximal percent increase in diameter above baseline (mean value of measures obtained during 1 minute before cuff inflation).
Flow Mediated Dilation, Acute, Positive Control	From before consumption on day 1 to 2 hours post consumption on day 1	Flow mediated dilation (FMD) measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (Resting stage); * 5 minutes of forearm occlusion at 300±30 mmHg (cuff occlusion stage), just below the elbow 2-5 cm from antecubital crease); * 4 minutes FMD scan, which started immediately after release of occlusion (reactive hyperaemia stage); * When the artery had returned to baseline a second 1 minute scan was taken; * 25 µg sublingual glyceryl trinitrate (GTN) was given to the subject; * 5 minutes GTN scan to assess the endothelium-independent dilation FMD and response to GTN was calculated as maximal percent increase in diameter above baseline (mean value of measures obtained during 1 minute before cuff inflation).
Flow Mediated Dilation, Chronic, Positive Control	From before consumption on day 1 to before consumption day 8	Flow mediated dilation (FMD) measurement included the following steps: * 1 minute base scan to measure the baseline diameter of artery (Resting stage); * 5 minutes of forearm occlusion at 300±30 mmHg (cuff occlusion stage), just below the elbow 2-5 cm from antecubital crease); * 4 minutes FMD scan, which started immediately after release of occlusion (reactive hyperaemia stage); * When the artery had returned to baseline a second 1 minute scan was taken; * 25 µg sublingual glyceryl trinitrate (GTN) was given to the subject; * 5 minutes GTN scan to assess the endothelium-independent dilation FMD and response to GTN was calculated as maximal percent increase in diameter above baseline (mean value of measures obtained during 1 minute before cuff inflation).

Trial Locations

Locations (1)

Azienda Ospedaliero-Universitaria Pisana, Centro di Farmacologia Clinicaper la Sperimentazione dei Farmaci; 🇮🇹 Pisa, Italy