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Trial registered on ANZCTR


Registration number
ACTRN12609000509268
Ethics application status
Approved
Date submitted
10/06/2009
Date registered
29/06/2009
Date last updated
6/07/2012
Type of registration
Prospectively registered

Titles & IDs
Public title
The effects of green tea and exercise on cardiovascular health
Scientific title
The effects of exercise based lifestyle interventions with green tea supplementation on metabolic, autonomic, and cardiovascular function in overweight males.
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Overweight and obesity 236961 0
Cardiovascular disease 237094 0
Condition category
Condition code
Other 237309 237309 0 0
Research that is not of generic health relevance and not applicable to specific health categories listed above
Cardiovascular 237360 237360 0 0
Normal development and function of the cardiovascular system

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The project will be investigating the effect of green tea capsules (GTC) acutely (one off ingestion of GTC) and chronically (8 weeks ingestion of GTC) on vascular health. Also the ingestion of GTC and its interaction with moderate intensity of exercise will be examined. A double blinded cross over design will be used in the study. Both acute and chronic settings will consist of two different interventional arms; ingestion of GTC (arm 1) and GTC plus exercise (arm 2). In the acute and chronic settings, the dose of GTC will be 1500 mg of GTC containing 375 mg of epigallocatechin gallate (EGCG), which will be taken orally in the morning. The exercise intensity for both settings will be at 65% of maximal oxygen uptake (VO2max) for 30 minutes. Thus, in the acute setting, cardiovascular function will be assessed following ingestion of one GTC (arm 1) then a week later (following a one week of wash out period) participants will perform exercise on a bike following ingestion of GTC (arm 2). In a chronic setting, participants will be provided GTC for the duration of 8 weeks. The GTC (1500 mg of GTC containing 375 mg of EGCG) will be taken orally once in the morning for 8 weeks (arm 1). Cardiovascular function then will be assessed at pre, 4 weeks, and 8 weeks post ingestion of GTC. Following one week of wash out, participants will ingest GTC every morning plus perform one-on-one sessions of supervised moderate intensity exercise at 65% of VO2max for 30 minutes, 3 times/week for 8 weeks (arm 2). Cardiovascular function then will be assessed at pre, 4 weeks, and 8 weeks post GTC plus exercise.
Intervention code [1] 236735 0
Lifestyle
Intervention code [2] 236736 0
Other interventions
Comparator / control treatment
Subjects will act as their own controls in a placebo condition. The placebo will be 1500 mg of a cellulose capsule that will be taken orally. In acute setting, the placebo will be taken one off in the morning, whereas in the chronic setting, the placebo will be taken once in the morning for 8 weeks. The exercise will be carried out in the same manner for both GTC and placebo treatments.
Control group
Placebo

Outcomes
Primary outcome [1] 238124 0
Vascular function (e.g., forearm blood flow) will be assessed using Hokanson plethysmograph. Arterial stiffness will be assessed using SphymoCor. Whereas heart rate will be monitored through electrocardiograph (ECG). Blood pressure will be assessed using a beat-by beat blood pressure monitor.
Timepoint [1] 238124 0
The vascular change following green tea ingestion will be assessed at regular intervals (every 20 minutes) up to 2 hours. During the chronic ingestion of GTT, vascular change will be assessed at pre (week 0), during (week 4), and post treatment (week 8) same as the above intervals.
Secondary outcome [1] 242333 0
The metabolic response will be assessed through blood chemicals, such as assessment of insulin using Enzyme-Linked Immunosorbent Assay (ELISA) kit and blood lipid profiles (using Cholestech). Whereas the autonomic responses (heart rate and blood pressure using ECG and blood pressure monitor) will be assessed while the mental challenge task (word conflict task/Stroop task) is administered to the participants.
Timepoint [1] 242333 0
The metabolic and cardiac response will be assessed at pre (baseline), 4 weeks, and 8 weeks post intervention.

Eligibility
Key inclusion criteria
The criteria for study entry is a body mass index (BMI) between 25-35 kg/m2 and not to be involved in regular exercise (eg., exercise 4-5 times per week at hard intensity for more than 4 years).
Minimum age
18 Years
Maximum age
35 Years
Gender
Males
Can healthy volunteers participate?
Yes
Key exclusion criteria
All subjects who are on medication that influences cardiovascular and autonomic function and those who are diseased (eg., youthful cardiac events) will be screened out of the study.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 237134 0
Self funded/Unfunded
Name [1] 237134 0
Address [1] 237134 0
Country [1] 237134 0
Australia
Primary sponsor type
University
Name
University of New South Wales
Address
High Street
Randwick NSW 2052
Country
Australia
Secondary sponsor category [1] 4624 0
None
Name [1] 4624 0
Address [1] 4624 0
Country [1] 4624 0

Ethics approval
Ethics application status
Approved

Summary
Brief summary
Overweight individuals typically possess metabolic and vascular problems. Most overweight individuals have high levels of fat and sugar in their blood and also typically carry a lot of fat around their abdomen. Overweight individuals also possess problems in their arteries and veins which become stiff and are unable to stretch easily. Thus, the purpose of the study is to examine cardiovascular function following green tea supplement and its combination with exercise both acutely and chronically. It is hypothesised that (1) green tea supplement will reduce cardiovascular dysfunction in overweight males; (2) a combination of green tea supplement and exercise will normalize cardiovascular dysfunction possessed by the overweight males.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 29723 0
Address 29723 0
Country 29723 0
Phone 29723 0
Fax 29723 0
Email 29723 0
Contact person for public queries
Name 12970 0
Yati Boutcher
Address 12970 0
252, F20 Goodsell building
School of Medical Sciences, Faculty of Medicine
University of New South Wales
High Street, Randwick NSW 2052
Country 12970 0
Australia
Phone 12970 0
61-2-9385 2419
Fax 12970 0
Email 12970 0
y.boutcher@unsw.edu.au
Contact person for scientific queries
Name 3898 0
Yati Boutcher
Address 3898 0
252, F20 Goodsell building
School of Medical Sciences, Faculty of Medicine
University of New South Wales
High Street, Randwick NSW 2052
Country 3898 0
Australia
Phone 3898 0
61-2-9385 2419
Fax 3898 0
Email 3898 0
y.boutcher@unsw.edu.au

No information has been provided regarding IPD availability
Summary results
No Results