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Trial registered on ANZCTR


Trial ID
ACTRN12605000280606
Ethics application status
Approved
Date submitted
31/08/2005
Date registered
2/09/2005
Date last updated
4/01/2011
Type of registration
Retrospectively registered

Titles & IDs
Public title
Isocapnic intermittent hypoxia and endothelial dysfunction
Scientific title
The effects of nitric oxide synthase inhibition on arterial stiffness during short term hypoxic exposure in healthy men
Secondary ID [1] 134 0
Sydney South West Area Health Service Ethic Committee: X03-0093
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Healthy control subjects 368 0
Condition category
Condition code
Other 433 433 0 0

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Subjects will be infused with L-N monomethyl arginine (LNMMA) and saline (placebo) in a single blinded randomized design on two separate days to assess the effect of nitric oxide synthase inhibition on arterial stiffness. Initially there will be a 10 minute baseline period. Then the LNMMA or saline will be infused over 5 minutes, after which there will be another 5 minute baseline period. Following this there will be the 20 minute period of hypoxia and then a 10 minute recovery period. During this the subjects will breathe through a mouthpiece connected to special equipment which delivers different gas mixtures and enables the delivery of the hypoxic exposure. Heart rate blood pressure, arterial stiffness ( via pulse wave analysis), and peripheral vasoconstriction (via peripheral arterial tonometry PAT) will be measured.
Intervention code [1] 316 0
None
Comparator / control treatment
Saline (placebo)
Control group
Placebo

Outcomes
Primary outcome [1] 494 0
To measure the effect of LNMMA, a nitric oxide synthase inhibitor, on the change in AIx (an index of arterial stiffness), with hypoxic exposure
Timepoint [1] 494 0
Measured continuously during the 50 minute protocol.
Secondary outcome [1] 1060 0
Changes in heart rate
Timepoint [1] 1060 0
This will be measured continously during the 50 minute protocol.
Secondary outcome [2] 1061 0
Changes in blood pressure
Timepoint [2] 1061 0
This will be measured continously during the 50 minute protocol.
Secondary outcome [3] 1062 0
Changes in peripheral arterial tonometry
Timepoint [3] 1062 0
This will be measured continously during the 50 minute protocol.
Secondary outcome [4] 1063 0
Changes in ventilation with hypoxic exposure.
Timepoint [4] 1063 0
This will be measured continously during the 50 minute protocol.

Eligibility
Key inclusion criteria
Healthy men
Minimum age
Not stated
Maximum age
Not stated
Gender
Males
Can healthy volunteers participate?
No
Key exclusion criteria
History of obstructive sleep apnoea or cardiovascular or respiratory disease, Smoker, Treatment with cardiovascular or respiratory medication.

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



Intervention assignment
Crossover
Other design features
Phase
Phase 3
Type of endpoint(s)
Safety/efficacy
Statistical methods / analysis

Recruitment
Recruitment status
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] 483 0
Government body
Name [1] 483 0
National Health and Medical Research Council
Address [1] 483 0
Country [1] 483 0
Australia
Primary sponsor type
Government body
Name
NHMRC
Address
Country
Australia
Secondary sponsor category [1] 390 0
Government body
Name [1] 390 0
NHMRC
Address [1] 390 0
Country [1] 390 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 1462 0
Royal Prince Alfred Hospital
Ethics committee address [1] 1462 0
Ethics committee country [1] 1462 0
Australia
Date submitted for ethics approval [1] 1462 0
Approval date [1] 1462 0
Ethics approval number [1] 1462 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 35927 0
Address 35927 0
Country 35927 0
Phone 35927 0
Fax 35927 0
Email 35927 0
Contact person for public queries
Name 9505 0
Ms Wendy Taylor
Address 9505 0
PO Box M77
Missenden Road
Camperdown NSW 2050
Country 9505 0
Australia
Phone 9505 0
+61 2 95156578
Fax 9505 0
+61 2 95505865
Email 9505 0
wtaylor@woolcock.org.au
Contact person for scientific queries
Name 433 0
Dr Hima Vedam
Address 433 0
PO Box M77
Missenden Road
Camperdown NSW 2050
Country 433 0
Australia
Phone 433 0
+61 404072392
Fax 433 0
Email 433 0
himav@mail.med.usyd.edu.au