None listed
Conditions
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.
Interventions
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 m
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.
Sponsors
Woolcock Institute of Medical Research
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used)
Eligibility
Sex/Gender
All
Age
21 Years to 65 Years
Healthy volunteers
No
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
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.
Outcome results
None listed