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Trial registered on ANZCTR


Registration number
ACTRN12610000714088
Ethics application status
Approved
Date submitted
25/08/2010
Date registered
27/08/2010
Date last updated
15/12/2015
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effect of genetic background on blood pressure response to weight reduction
Scientific title
To examine the effect of the CYP4F2 G1347A polymorphism on blood pressure and plasma and urinary 20-HETE responses to weight reduction in overweight participants
Secondary ID [1] 252569 0
nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
metabolic syndrome 258053 0
Condition category
Condition code
Cardiovascular 258213 258213 0 0
Hypertension
Metabolic and Endocrine 258245 258245 0 0
Metabolic disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Overweight men aged between 20 and 70 yrs and post-menopausal women less than 70yrs will be screened for two genetic polymorphisms called CYP4F2 G1347A and CYP4A11 T8590C that affect 20-HETE levels. The screening visit will take approximately 1 hour and requires donation of a small blood sample (10ml). Genetic material (DNA) will be isolated from this blood sample in for identification of the two polymorphisms. Two groups will be studied. A group that are carriers of the A allele of the CYP4F2 G1347A polymorphism but who do not have the CYP4A11 T8590C polymorphism and a control group that has neither polymorphism. Both groups will receive one on one 1 hour sessions with a dietitian every 2 weeks to assist them to reduced their weight (by ~4-8kg) over a 12 week period. At the end of 12 weeks, volunteers will be counselled every 2 weeks by the dietitain about how to maintain their weight for a 4 week period of weight stabilisation.
Intervention code [1] 257085 0
Lifestyle
Comparator / control treatment
The comparitor group is the group that has neither of the polymorphisms undergoing the same weight loss intervention,
Control group
Uncontrolled

Outcomes
Primary outcome [1] 259077 0
Blood pressure using a 24 hor ambulatory blood pressure monitor
Timepoint [1] 259077 0
Baseline, 12 weeks and 16 weeks
Primary outcome [2] 259091 0
Plasma 20-HETE measured by gas chromatography mass spectrometry
Timepoint [2] 259091 0
Baseline, 12 weeks and 16 weeks
Primary outcome [3] 259092 0
Urinary 20-HETE measured from a 24 hour urine collection by gas chromatography mass spectrometry
Timepoint [3] 259092 0
Baseline, 12 weeks and 16 weeks
Secondary outcome [1] 265362 0
plasma F2-isoprostanes measured by gas chromatography mass spectrometry
Timepoint [1] 265362 0
Baseline, 12 weeks and 16 weeks
Secondary outcome [2] 265385 0
Urinary F2-isoprostanes measured in a 24hr urine collection by gas chromatography mass spectrometry
Timepoint [2] 265385 0
Baseline, 12 weeks and 16 weeks

Eligibility
Key inclusion criteria
Volunteers will undergo a medical examination conducted by a physician to assess their suitability for the study. Overweight men with waist circumference greater than or equal to 102cm and overweight post-menopausal women with with waist circumference greater than or equal to 88cm who have a systolic blood pressure greater or equal to 120mmHg and body mass index between 25 and 40. They will be screened for two genetic polymorphisms called CYP4F2 G1347A and CYP4A11 T8590C that affect 20-HETE levels. Two groups will be studied. A group that are carriers of the A allele of the CYP4F2 G1347A polymorphism but who do not have the CYP4A11 T8590C polymorphism and a control group that has neither polymorphism.
Minimum age
20 Years
Maximum age
70 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
smoking, diabetes, Body mass index >40, taking blood pressure or lipid lowering medication, drinking more than 3 standard drinks /day or 4 standard drinks in a single session, impaired renal function, a history of chronic disease.

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
The volunteers are enrolled according to their genotype. All suitable volunteers undergo the weight reduction intervention.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint(s)
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)

Funding & Sponsors
Funding source category [1] 257537 0
Government body
Name [1] 257537 0
National Health & Medical Research Council Of Australia
Address [1] 257537 0
Level 5, 20 Altara St, Canberra
Country [1] 257537 0
Australia
Primary sponsor type
Individual
Name
Research Assistant Professor Anne Barden
Address
School of Medicine & Pharmacology,
Royal Perth Hosiptal Unit,
PO Box X2213, Perth, WA 6847
Country
Australia
Secondary sponsor category [1] 256763 0
Individual
Name [1] 256763 0
Professor Lawrie Beilin
Address [1] 256763 0
School of Medicine & Pharmacology,
Royal Perth Hosiptal Unit,
PO Box X2213, Perth, WA 6847
Country [1] 256763 0
Australia
Other collaborator category [1] 251458 0
Individual
Name [1] 251458 0
Professor Kevin Croft
Address [1] 251458 0
School of Medicine & Pharmacology,
Royal Perth Hosiptal Unit,
PO Box X2213, Perth, WA 6847
Country [1] 251458 0
Australia
Other collaborator category [2] 251459 0
Individual
Name [2] 251459 0
Professor Ian Puddey
Address [2] 251459 0
School of Medicine & Pharmacology,
Royal Perth Hosiptal Unit,
PO Box X2213, Perth, WA 6847
Country [2] 251459 0
Australia
Other collaborator category [3] 251460 0
Individual
Name [3] 251460 0
Dr Natalie Ward
Address [3] 251460 0
School of Medicine & Pharmacology,
Royal Perth Hosiptal Unit,
PO Box X2213, Perth, WA 6847
Country [3] 251460 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 259566 0
University of Western Australia Human Research Ethics Committee
Ethics committee address [1] 259566 0
35 Stirling Hwy, Crawley, Western Australia 6009
Ethics committee country [1] 259566 0
Australia
Date submitted for ethics approval [1] 259566 0
Approval date [1] 259566 0
18/12/2009
Ethics approval number [1] 259566 0
RA4/1/2661

Summary
Brief summary
The effectiveness of treatments to reduce heart disease risk can vary a great deal between individuals. This is partly due to an individual’s genetic makeup. Fatty acid metabolites called cytochrome P450 metabolites of arachidonic acid (CYP450-AAM) can act on blood vessels and the kidney to regulate blood pressure. One of these metabolites (20-HETE) is known to be affected by body weight. We will study volunteers with two different genetic make-ups that have different effects on the levels of 20-HETE, to see if they affect blood pressure and heart disease risk. We will assess whether having either genetic make-up causes a different blood pressure and plasma and urinary 20-HETE response when volunteers reduce their weight.
Trial website
Trial related presentations / publications
Presentation at High Blood Pressure Research Council 05/12/2013
A SINGLE NUCLEOTIDE POLYMORPHISM OF THE CYP4F2 GENE IMPAIRS MAINTENANCE OF LOWER BP AFTER WEIGHT LOSS
Publication
The effect of a single nucleotide polymorphism of the CYP4F2 gene on blood pressure and 20-hydroxyeicosatetraenoic acid excretion after weight loss by Natalie C. Ward, Kevin D. Croft, Ian B. Puddey, Michael Phillips, Frank van Bockxmeer, Lawrence J. Beilin, and Anne E. Barden in Journal of Hypertension 2014, 32:1495–1502
Public notes

Contacts
Principal investigator
Name 31569 0
Prof Anne Barden
Address 31569 0
School of Medicine & Pharmacology
Level 4 MRF Building
Rear 50, Murray St
Perth WA 6000
Country 31569 0
Australia
Phone 31569 0
618 9224 0272
Fax 31569 0
Email 31569 0
anne.barden@uwa.edu.au
Contact person for public queries
Name 14816 0
Prof Anne Barden
Address 14816 0
School of Medicine & Pharmacology,
Royal Perth Hospital Unit,
GPO Box X2213
Perth, Western Australia, 6847
Country 14816 0
Australia
Phone 14816 0
618 9224 0272
Fax 14816 0
618 9224 0246
Email 14816 0
anne.barden@uwa.edu.au
Contact person for scientific queries
Name 5744 0
Prof Anne Barden
Address 5744 0
School of Medicine & Pharmacology,
Royal Perth Hospital Unit,
GPO Box X2213
Perth, Western Australia, 6847
Country 5744 0
Australia
Phone 5744 0
618 9224 0272
Fax 5744 0
618 9224 0246
Email 5744 0
anne.barden@uwa.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