The Effect of OSA on Brain Waste Clearance

Who can take part

• Community dwelling adults aged 35-65 years
• Polysomnography-confirmed severe OSA with apnea hypopnea index (AHI) ≥ 30/hour, with Non-Rapid Eye Movement (NREM) AHI ≥ 15/hour
• Established CPAP use for treatment of OSA with compliance of > 3 months, with ≥ 5 hours use per night for > 5 nights per week
• Willing to withdraw from CPAP use for 14 nights
• Able to give informed verbal and written consent
• Fluent in spoken, and comprehension of English

Who cannot take part

• Regular use of medications which affect sleep (e.g.: benzodiazepines, opioids, stimulants, sedating antihistamines)
• Vulnerable to driving impairment without CPAP therapy/upon withdrawal of CPAP therapy, as assessed by: (a) positive response(s) to screening questions in the modified ASTN-Motor Vehicle Accident Questionnaire, reporting driving accidents and/or impairments prior to established CPAP therapy; AND/OR (b) the participant's treating physician
• Prior history of severe COVID-19 infection involving significant neurological symptoms (e.g.: reduced level of consciousness, delirium, encephalopathy) - warranting hospitalization
• Not up to date with the COVID-19 vaccination schedule - as per the current Australian Technical Advisory Group on Immunization (ATAGI) definition for individuals aged 16 years and over - at the time of writing this Protocol, defined as having:; Received 2 primary doses of any Therapeutic Goods Administration (TGA)-approved or TGA-recognized COVID-19 vaccine at least 14 days apart (except for the Janssen COVID-19 vaccine, where only 1 primary dose is required); PLUS; A booster dose of a TGA-approved COVID-19 vaccine (Pfizer, Moderna or AstraZeneca) at a recommended interval of 3-6 months after the receipt of 2nd primary dose; OR; For severely immunocompromised individuals: received 3 primary doses of any TGA-approved or TGA-recognized COVID-19 vaccine, with dose 3 administered within 6 months of receiving dose 2
• History of severe cardiovascular disease (e.g.: stroke, myocardial infarction, atrial fibrillation)
• Presence of cognitive impairment and/or established diagnosis of dementia
• Regular 24-hour shift workers, presence of jetlag, or history of trans-meridian travel (crossing 2 or more time zones) in the past 2 weeks
• Current COVID-19 infection and/or experience of ongoing symptoms/sequelae following a recent COVID-19 infection
• Other medical conditions deemed by study physicians to warrant exclusion
• Commercial drivers (e.g.: drivers of heavy vehicles, public passenger vehicles, or vehicles requiring dangerous goods driver license)
• Advice against withdrawal of CPAP treatment, as determined by the participant's treating physician or study physician