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Trial registered on ANZCTR


Trial ID
ACTRN12605000066684
Ethics application status
Approved
Date submitted
1/08/2005
Date registered
2/08/2005
Date last updated
24/01/2011
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effect of Obstructive Sleep Apnoea (OSA) and its treatment with Continuous Positive Airways Pressure (CPAP) on lipid metabolism
Scientific title
The effect of Obstructive Sleep Apnoea (OSA) and its treatment with Continuous Positive Airways Pressure (CPAP) on lipid metabolism
Secondary ID [1] 93 0
In patients with sleep apnoea, is treatment with nasal CPAP better than placebo in improving postprandial lipidemia?
Universal Trial Number (UTN)
Trial acronym
PPLOSA
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obstructive Sleep Apnoea (OSA) 138 0
Condition category
Condition code
Respiratory 158 158 0 0
Sleep apnoea

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Subjects with OSA will be studied before and after 2 months of Continuous Positive Airway Pressure (CPAP) therapy or Sham CPAP in a randomised crossover design. Stage 1 will assess the magnitude of Post Prandial Lipide-mia (PPL) in subjects across a 24-hour period before and after CPAP to de-termine how OSA may alter lipid metabolism. Markers of oxidative stress will also be measured to determine how PPL and OSA may enhance oxidative stress. Stage 2 will use Magnetic Resonance Imaging (MRI) to monitor changes in abdominal fat deposits and 1H Magnetic Resonance Spectroscopy (MRS) to monitor changes in intra-hepatocellular lipid (IHCL) levels following CPAP or Sham CPAP treatment. Patients are encouraged to use either device on a nightly basis for the entire sleep period during each of the two months on treatment. CPAP is the recommended therapy for sleep apnoea. Treatment involves delivery of pressurised air from a CPAP machine to the upper airway via a tube connected to nasal mask which is worn during sleep. The pressurised air acts to pneumatically splint the airway, preventing collapse during sleep. SHAM CPAP is an identicle device and mask interface but air is not delivered at a pressure sufficient to prevent airway collapse. Each treatment involves wearing the mask during all hours whilst asleep. Each treatment arm (CPAP or SHAM CPAP) will last for 2 months.
Outcome measures will be determined at baseline (prior to treatment) and at the end of each treatment arm.
Intervention code [1] 88 0
Treatment: Devices
Comparator / control treatment
Sham CPAP – a device that is identical to therapeutic CPAP but which delivers an ineffective therapeutic pressure
Control group
Placebo

Outcomes
Primary outcome [1] 193 0
Total Area under the Triglyceride concentration curve (AUC) over 24 hours.
Timepoint [1] 193 0
at Baseline and at 2 months after each of CPAP or Sham CPAP
Secondary outcome [1] 449 0
Arterial Stiffness ? Aortic Augmentation Index
Timepoint [1] 449 0
at Baseline and at 2 months after each of CPAP or Sham CPAP
Secondary outcome [2] 450 0
Hepatocellular Lipid Concentration
Timepoint [2] 450 0
at Baseline and at 2 months after each of CPAP or Sham CPAP
Secondary outcome [3] 244571 0
Visceral and Subcutaneous Abdominal Fat
Timepoint [3] 244571 0
at Baseline and at 2 months after each of CPAP or Sham CPAP
Secondary outcome [4] 244572 0
Oxidative stress markers
Timepoint [4] 244572 0
at Baseline and at 2 months after each of CPAP or Sham CPAP

Eligibility
Key inclusion criteria
Body Mass Index (BMI) less than or equal to 35. Fasting Triglycerides < 4mmol/L. Respiratory Disturbance Index (RDI) of >= 25 and Oxygen Desaturation Index (ODI) >=20
Minimum age
21 Years
Maximum age
65 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Stage 1 Exclusion criteria: 1. Clinically significant co morbidity, including any unstable cardiovascular, gastrointestinal, metabolic, pulmonary (e.g., asthma, COPD), renal, neurological, hepatic, hematologic, immunologic, endocrine, psychiatric illness and/or neoplastic disease based on Principal Investigator judgment. 2. Patients who are on fibrate (lipid lowering) medications. 3. Fasting triglycerides > 4mmol/l 4. Patients unable to read and understand the Patient Information Sheets or Consent Forms. Stage 2 Exclusion criteria: 1. Claustrophobia. 2. Any in vivo Ferro-magnetic material such as a pacemaker, Neuro stimulator, Cochlear Implants, aneurysm clip, metal implants, shrapnel injuries, ever worked with metal, ever had metal in their eye or if they had any surgery.
Stage 3 Exclusion criteria: 1. Clinically significant co morbidity, including any unstable cardiovascular, gastrointestinal, metabolic, pulmonary (e.g., asthma, COPD), renal, neurological, hepatic, hematologic, immunologic, endocrine, psychiatric illness and/or neoplastic disease based on Principal Investigator judgment. 2. Patients unable to read and understand the Patient Information Sheets or Consent Forms. 3. Medication exclusions - Beta blockers and Beta 2 agonists.

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)
Subjects will be recruited from sleep clinics. Patients will be randomised into either treatment arm by using a randomisation sequence. The randomisation sequence will be generated with random permuted blocks. Allocation con-cealment will be maintained by sequentially numbered, opaque sealed enve-lopes. Both patients and investigators will be blinded to the order of treatment.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The randomisation sequence will be generated with random permuted blocks.]
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
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] 211 0
Government body
Name [1] 211 0
National Health & Medical Research Council project grant
Address [1] 211 0
Canberra ACT
Country [1] 211 0
Australia
Primary sponsor type
Other
Name
Woolcock Institute of Medical Research
Address
431 Glebe Point Road GLEBE NSW 2037
Country
Australia
Secondary sponsor category [1] 158 0
Hospital
Name [1] 158 0
Royal Prince Alfred Hospital, University of Sydney
Address [1] 158 0
Missenden Road, Camperdown NSW 2050
Country [1] 158 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 974 0
Sydney South West Area Health Service
Ethics committee address [1] 974 0
Ethics committee country [1] 974 0
Australia
Date submitted for ethics approval [1] 974 0
01/03/2005
Approval date [1] 974 0
01/04/2006
Ethics approval number [1] 974 0
X05-0128

Summary
Brief summary
Target sample size = 30 subjects for Stages 1 and 2. The primary aim of the study is to determine whether treatment for Obstructive Sleep Apnoea with nasal Continuous Positive Airway Pressure therapy will improve triglyceride metabolism over 24 hours. Triglyceride concentrations in the blood increase after meals and the reduced rate at which they are metabolised is a marker of increased cardiovascular risk. We hypothesise that treatment of sleep apnoea will improve post prandial levels of triglycerides.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 36288 0
Address 36288 0
Country 36288 0
Phone 36288 0
Fax 36288 0
Email 36288 0
Contact person for public queries
Name 9277 0
Ms Joan Torony
Address 9277 0
PO Box M77
Missenden Road
Camperdown NSW 2050
Country 9277 0
Australia
Phone 9277 0
+61 2 91140410
Fax 9277 0
+ 61 2 91140014
Email 9277 0
volunteers@woolcock.org.au
Contact person for scientific queries
Name 205 0
Mr Craig Phillips
Address 205 0
PO Box M77 Missenden Road Camperdown NSW 2050
Country 205 0
Australia
Phone 205 0
+61 2 91140448
Fax 205 0
+ 61 2 91140014
Email 205 0
cphillip@mail.usyd.edu.au