Grant: Travel Awards - Institute Community Support

Obstructive sleep apnea (OSA) is a common, chronic medical disorder that increases the risk of cognitive impairment (trouble remembering, concentrating or making decisions). Patients with OSA stop breathing (called apnea) intermittently during sleep because their throat or windpipe collapses and blocks (obstructs) the flow of air into the lungs. With each apnea the body is starved of oxygen and the level of oxygen in the blood falls. This continues for 20 or more seconds until the apnea is stopped by awakening from sleep which re-opens the windpipe thereby allowing air (and oxygen) to flow back into the lungs. The oxygen level in the blood returns to normal and the patient quickly returns to sleep which allows the windpipe to close again, causing the same cycle of events to recur. In severe cases, apneas can occur more than once every minute throughout the night and have often been present for several years before the condition is identified and treated. The repetitive rise and fall in the blood oxygen level is believed to be why OSA increases the risk of cognitive impairment. However, not all OSA patients will develop cognitive impairment and the relationship between the repetitive rises and falls in oxygen levels with untreated OSA and cognitive impairment is muddled by additional factors such as genetic pre-disposition to cognitive impairment, how long a patient has had OSA before being diagnosed, cognitive reserve (the brain's ability to maintain proper cognition after brain damage has occurred), co-existing sleepiness, age, gender and other co-morbidities (e.g, high blood pressure, kidney disease). Thus, the purpose of this study is to determine the prevalence and severity of cognitive impairment within a population of OSA patients diagnosed at three sleep clinics across Canada, and to identify biomarkers to help predict which OSA patients are at greatest risk for cognitive impairment.