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Trial registered on ANZCTR


Registration number
ACTRN12609000023257
Ethics application status
Approved
Date submitted
28/11/2008
Date registered
12/01/2009
Date last updated
12/11/2013
Type of registration
Prospectively registered

Titles & IDs
Public title
Acute effects of resveratrol on circulatory function in obese people with elevated blood pressure.
Scientific title
Resveratrol supplementation for improving endothelium dependent vasodilator function and attenuating pressor responses to exercise in obese people with elevated blood pressure.
Secondary ID [1] 283576 0
Nil
Universal Trial Number (UTN)
N/A
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Endothelial vasodilator function 4004 0
Blood pressure response to exercise 4005 0
Condition category
Condition code
Cardiovascular 4204 4204 0 0
Diseases of the vasculature and circulation including the lymphatic system
Cardiovascular 4205 4205 0 0
Hypertension

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Volunteers will be required to consume three doses of resveratrol (30, 90 or 270mg on one occasion per dose).
There will be four separate visits (of one hour duration each) to the research centre which will occur with a one week washout between visits. At each visit the participant will consume one dose of resveratrol (or placebo) per visit.
Measurements of endothelial vasodilator function and blood pressure responses to exercise will begin one hour after consumption of each single dose of resveratrol. These measures will be repeated at each visit.
Resveratrol will be administered orally in capsules. Each of the three doses of resveratrol consists of multiple capsules; all capsules that make up a single dose will be consumed at once.
Doses will be made up of combinations of 15 and 75 mg resveratrol capsules as follows:

1) 30 mg: 2 capsules of 15 mg + 4 placebo capsules
2) 90 mg: 1 capsule of 75 mg + 1 capsule of 15 mg + 4 placebo
3) 270 mg: 3 capsules of 75 mg + 3 of 15 mg
Intervention code [1] 3730 0
Lifestyle
Comparator / control treatment
Placebo capsules are identical in appearance to the active capsules but contain an inert filler consisting of Calcium Hydrogen Phosphate, microcrystalline cellulose (MCC) of various particle sizes including Prosolv 50 and talcum powder (hydrated magnesium silicate).
There are a total of four testing visits for this trial. Three will include the consumption of a single dose of resveratrol and one will be the placebo and each visit will be one week apart.
Volunteers will take an oral dose of six placebo capsules all at once on a single occasion.
Measurements of endothelial vasodilator function and blood pressure responses to exercise will begin one hour after consumption of the placebo.
Control group
Placebo

Outcomes
Primary outcome [1] 5100 0
Degree of change in vasodilator function assessed by flow mediated dilatation in the brachial artery.
Timepoint [1] 5100 0
There will be four time points which will occur one week apart. At each visit testing will commence one hour after consumption of each dose of resveratrol or placebo.
Secondary outcome [1] 8569 0
Blood pressure responses to exercise will be assessed continuously using a Finapres blood pressure monitor, which measures blood pressure non-invasively through the finger.
Timepoint [1] 8569 0
There will be four time points which will occur one week apart. At each visit testing will commence one hour after consumption of each dose of resveratrol or placebo.
Secondary outcome [2] 8571 0
A small blood sample will be taken one hour after the consumption of each dose of resveratrol or placebo to assess plasma levels of resveratrol.
Blood samples will be sent to DSM in Switzerland for analysis.
Timepoint [2] 8571 0
There will be four time points which will occur one week apart. At each visit testing will commence one hour after consumption of each dose of resveratrol or placebo.

Eligibility
Key inclusion criteria
Men or post-menopausal women (self reported cessation of menses for at least 12 months) aged 30 - 70 years.
b) Volunteers will be overweight or obese (Body mass index (BMI) ranging from 25kg/m2 to 35kg/m2), and
c) have high-normal BP or untreated mild primary hypertension (systolic BP 130-160 mmHg or Diastolic BP 85-100 mmHg)
d) but are otherwise healthy.

Volunteers will provide a blood sample on the first day of testing to assess blood chemistry, coagulation and hematology outcomes to ensure there are no underlying medical conditions that would influence the study outcomes.
Minimum age
30 Years
Maximum age
75 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
a) have cardiovascular disease, renal disease or diabetes
b) take BP lowering medication
c) have any other medical condition or treatments (including supplements) which, in the opinion of the investigators, may influence the outcome of the study
d) smoke or use nicotine replacement therapy

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Volunteers will be recruited via letter from database of previous participants in trial at the Nutritional Physiology Research Centre who have been identified as meeting the inclusion criteria. Volunteers will be requested to attend the research centre for a screening to assess their eligibility for the trial and enrolled based on body mass index and blood pressure values obtained at that visit.
Eligibility will be determined by the study coordinator. Volunteers will be required to consume each dose once, the order of which will be determined by a random number generator. Doses will be allocated a letter A-D for identification. The identity of the supplement will be held by an individual separate to the study which will not be decoded until all data has been analysed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation by using a randomization table created by a computer software (i.e., computerised sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Safety/efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
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)
SA

Funding & Sponsors
Funding source category [1] 4194 0
Commercial sector/Industry
Name [1] 4194 0
DSM Nutritional Products
Address [1] 4194 0
PO Box 2676
CH-4002 Basel
Country [1] 4194 0
Switzerland
Primary sponsor type
Individual
Name
Professor Peter Howe
Address
Nutritional Physiology Research Centre
University of South Australia, PO Box 2471
Adelaide, South Australia, 5001
Country
Australia
Secondary sponsor category [1] 3768 0
Individual
Name [1] 3768 0
Dr Narelle Berry
Address [1] 3768 0
Nutritional Physiology Research Centre
University of South Australia, PO Box 2471
Adelaide, South Australia, 5001
Country [1] 3768 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 6251 0
University of South Australia Human Research Ethics Committee
Ethics committee address [1] 6251 0
General Purpose Building, Mawson Lakes Campus,
Mawson Lakes Boulevard, Mawson Lakes,
South Australia, 5095
Ethics committee country [1] 6251 0
Australia
Date submitted for ethics approval [1] 6251 0
Approval date [1] 6251 0
27/11/2008
Ethics approval number [1] 6251 0
P237/08

Summary
Brief summary
It is well established that obesity and elevated blood pressure can lead to impaired vascular function. However, it is less clear how impaired blood vessel function affects cardiovascular and, consequently, blood pressure responses during exercise. Exaggerated blood pressure responses to exercise can be an early risk factor for the development of future hypertension.
The aim of this study is to establish a dose/response relationship for the effect of resveratrol on endothelial vasodilator function as measured by flow mediated dilation (FMD) and blood pressure (BP), both at rest and during exercise, in volunteers who are overweight/obese with elevated BP.
The results of this study will inform the design of future trials which will explore the effect of combinations of resveratrol and other vasoactive nutrients on cardiovascular and mental health.
Trial website
N/A
Trial related presentations / publications
Wong, R H X; Howe, P R C; Buckley, J D; Coates, A M; Kunz, I; Berry, N M, Acute resveratrol supplementation improves flow-mediated dilatation in overweight/obese individuals with mildly elevated blood pressure, Nutrition, metabolism, and cardiovascular diseases, 2011, 21(11), 851 – 856.
Public notes

Contacts
Principal investigator
Name 29152 0
Prof Peter Howe
Address 29152 0
University of Newcastle
School of Biomedical Sciences & Pharmacy
University Drive
Callaghan
NSW 2308
Country 29152 0
Australia
Phone 29152 0
+61 2 49217309
Fax 29152 0
Email 29152 0
peter.howe@newcastle.edu.au
Contact person for public queries
Name 12309 0
Dr Dr Narelle Berry
Address 12309 0
Nutritional Physiology Research Centre
University of South Australia, PO Box 2471
Adelaide, South Australia, 5001
Country 12309 0
Australia
Phone 12309 0
+61 8 83021817
Fax 12309 0
+61 8 83022178
Email 12309 0
narelle.berry@unisa.edu.au
Contact person for scientific queries
Name 3237 0
Prof Professor Peter Howe
Address 3237 0
Nutritional Physiology Research Centre
University of South Australia, PO Box 2471
Adelaide, South Australia, 5001
Country 3237 0
Australia
Phone 3237 0
+61 8 83021200
Fax 3237 0
+61 8 83022178
Email 3237 0
peter.howe@unisa.edu.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary