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Trial registered on ANZCTR


Registration number
ACTRN12610000713099
Ethics application status
Approved
Date submitted
26/08/2010
Date registered
27/08/2010
Date last updated
15/02/2011
Type of registration
Prospectively registered

Titles & IDs
Public title
Mechanism of cardiovascular benefits of omega-3 fatty acids in hypertensive and normotensive subjects
Scientific title
Double-blinded, placebo controlled investigation of the cardiovascular benefits of omega-3 fatty acids in hypertensive and normotensive subjects
Secondary ID [1] 252573 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Hypertensive men and women 258056 0
Condition category
Condition code
Cardiovascular 258218 258218 0 0
Hypertension
Alternative and Complementary Medicine 258243 258243 0 0
Other alternative and complementary medicine
Cardiovascular 258244 258244 0 0
Normal development and function of the cardiovascular system

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Normotensive and Hypertensive subjects will receive 4x1 g placebo capsules/day (Sunola oil) for 3 weeks. Subjects will then be randomised to receive either 4x1g fish oil capsules/day (Blackmores Omega Heart, Blackmores Ltd, Australia) containing 2.52 g/day eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA), or 4x1g placebo capsules/day for 12 weeks. A final 3 week washout phase will follow in which subjects cease taking the capsules. Subjects will record daily blood pressure (BP) at home using an automated BP device for the 18 week trial. Fasted blood samples will be taken every three weeks, commencing at week 0. Subjects will undergo a cold pressor test, a hand grip test, and reactive hyperaemic response with measurements of BP, blood flow and heart rate variability at weeks 1, 3 and then at 3 weekly intervals.
Intervention code [1] 257088 0
Treatment: Other
Intervention code [2] 257102 0
Prevention
Comparator / control treatment
Data obtained from hypertensive subjects will be compared to data obtained from normotensive subjects. Hypertensive and normotensive subjects randomised to receive omega-3 fatty acids will be compared to hypertensive and normotensive subjects randomised to receive placebo. The trial will be double blinded.
Control group
Placebo

Outcomes
Primary outcome [1] 259080 0
Plasma endothelin levels analysed by enzyme linked immunosorbent assay.
Timepoint [1] 259080 0
Fasted blood collections will occur at 3 weekly intervals from baseline for 18 weeks.
Primary outcome [2] 259089 0
Blood flow will be measured using plethysmography.
Timepoint [2] 259089 0
Physiology tests will occur at weeks 1 and 3 weeks from baseline and then at 3 weekly intervals for up to 18 weeks.
Primary outcome [3] 259090 0
Heart rate variability will be measured by electrocardiography.
Timepoint [3] 259090 0
Physiology tests will occur at weeks 1 and 3 weeks from baseline and then at 3 weekly intervals for up to 18 weeks.
Secondary outcome [1] 265369 0
Omega-3 index using erythrocyte membranes and analysed by gas chromatography
Timepoint [1] 265369 0
Fasted blood collections will occur at 3 weekly intervals from baseline for 18 weeks.
Secondary outcome [2] 265382 0
Serum cholesterol levels will be measured by spectrophotometry.
Timepoint [2] 265382 0
Fasted blood collections will occur at 3 weekly intervals from baseline for 18 weeks.
Secondary outcome [3] 265383 0
Serum triglyceride levels will be measured by spectrophotometry.
Timepoint [3] 265383 0
Fasted blood collections will occur at 3 weekly intervals from baseline for 18 weeks.
Secondary outcome [4] 265384 0
Serum high density lipoprotein (HDL) levels will be measured by spectrophotometry.
Timepoint [4] 265384 0
Fasted blood collections will occur at 3 weekly intervals from baseline for 18 weeks.

Eligibility
Key inclusion criteria
Men or women with normal BP, or mild hypertension (140-159/90-99 mmHg). Subjects consume no more than 2 oily fish meals per week.
Minimum age
30 Years
Maximum age
85 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Subjects are not eligible to participate if they are currently taking medication to lower their blood pressure, are on a special diet eg. Atkins diet, Lo-Carbo diet and Zone diet, or have a high level of daily exercise. Other exclusions: unable to communicate in English, pregnant, infectious disease eg. human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS), hepatitis.

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)
Subjects are informed that this is a double-blinded, randomised, placebo controlled trial during the consent process. Capsules are packaged into containers that have no identifiers for the capsule content. Students working with the subjects are blinded to the treatment group. Treatment is allocated using randomisation software.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
To generate the random samples, software called R will be used.

R Development Core Team (2009). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0,
URL http://www.R-project.org.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Phase 3
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] 257539 0
University
Name [1] 257539 0
University of the Sunshine Coast
Address [1] 257539 0
90 Sippy Downs Drive,
Sippy Downs, QLD 4556
Country [1] 257539 0
Australia
Primary sponsor type
University
Name
University of the Sunshine Coast
Address
University of the Sunshine Coast
90 Sippy Downs Drive,
Sippy Downs, QLD 4556
Country
Australia
Secondary sponsor category [1] 256765 0
Individual
Name [1] 256765 0
Dr. Fraser Russell
Address [1] 256765 0
University of the Sunshine Coast
90 Sippy Downs Drive,
Sippy Downs, QLD 4556
Country [1] 256765 0
Australia
Other collaborator category [1] 251463 0
Individual
Name [1] 251463 0
Dr. Christopher Askew
Address [1] 251463 0
University of the Sunshine Coast
90 Sippy Downs Drive,
Sippy Downs, QLD 4556
Country [1] 251463 0
Australia
Other collaborator category [2] 251464 0
Individual
Name [2] 251464 0
Dr. Mark Holmes
Address [2] 251464 0
University of the Sunshine Coast
90 Sippy Downs Drive,
Sippy Downs, QLD 4556
Country [2] 251464 0
Australia
Other collaborator category [3] 251465 0
Individual
Name [3] 251465 0
Dr. Peter Brooks
Address [3] 251465 0
University of the Sunshine Coast
90 Sippy Downs Drive,
Sippy Downs, QLD 4556
Country [3] 251465 0
Australia
Other collaborator category [4] 251466 0
Individual
Name [4] 251466 0
Ms. Deborah Hitchen-Holmes
Address [4] 251466 0
University of the Sunshine Coast
90 Sippy Downs Drive,
Sippy Downs, QLD 4556
Country [4] 251466 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 259568 0
University of the Sunshine Coast Human Research Ethics Committee (HREC)
Ethics committee address [1] 259568 0
90 Sippy Downs Drive,
Sippy Downs, QLD, 4556
Ethics committee country [1] 259568 0
Australia
Date submitted for ethics approval [1] 259568 0
Approval date [1] 259568 0
16/06/2010
Ethics approval number [1] 259568 0
A/08/167

Summary
Brief summary
This study is testing the hypothesis that improvements in cardiovascular health with omega-3 fatty acid supplements are attributed to improvements in vascular function.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 31572 0
Address 31572 0
Country 31572 0
Phone 31572 0
Fax 31572 0
Email 31572 0
Contact person for public queries
Name 14819 0
Dr. Fraser Russell
Address 14819 0
University of the Sunshine Coast,
90 Sippy Downs Drive,
Sippy Downs,
Queensland, 4556
Country 14819 0
Australia
Phone 14819 0
+61 7 5459 4665
Fax 14819 0
+61 7 5459 4880
Email 14819 0
frussell@usc.edu.au
Contact person for scientific queries
Name 5747 0
Dr. Fraser Russell
Address 5747 0
University of the Sunshine Coast,
90 Sippy Downs Drive,
Sippy Downs,
Queensland, 4556
Country 5747 0
Australia
Phone 5747 0
+61 7 5459 4665
Fax 5747 0
+61 7 5459 4880
Email 5747 0
frussell@usc.edu.au

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