Sleeping position during sleep tests and at home.

None listed

Sleep disordered breathing is common with obstructive sleep apnoea (OSA) being the predominant type. OSA is the repetitive complete obstruction (apnoea) or partial obstruction (hypopnoea) of the collapsible part of the upper airway during sleep. Symptoms include excessive daytime sleepiness, unrefreshing sleep and fatigue. Numerous studies have shown that OSA is associated with depression, hypertension, stroke, motor vehicle accidents, and other cardiovascular disorders. Obstructive sleep apnoea (OSA) is diagnosed with polysomnography. Respiratory events, either apnoeas or hypopnoeas, frequently worsen when lying in the supine position. Previous data have shown that 60% of patients with OSA have supine predominant OSA (OSA that occurs at least twice as frequently in the supine position) and 25% of patients have OSA that is solely present when lying supine (Joosten et al, 2012). In this context, knowledge of OSA severity in different body positions is crucial to informing patient management. Polysomnography involves sleeping while attached to a significant number of sensors and electrodes to measure sleep quality and breathing and cardiac parameters. Because of the inconvenience of the test, patients commonly report that the position they sleep in during polysomnography does not represent what they usually do at home, with patients most commonly reporting that they sleep more in the supine position that they would normally do. However, patient reports of habitual body position during sleep may not necessarily be accurate and whether body position in polysomnography reflects habitual body position at home has never been systematically addressed in a research study. Therefore, our project aims to look at the body position of patients during polysomnography in comparison with the habitual body position of patients at home. We intend to enrol patients having sleep studies in our tertiary academic sleep unit, and provide them with a small, unobtrusive body position sensor to detect their habitual body position in their home over the subsequent week. We hypothesise that there will be a discordance between polysomnography determined body position and habitual sleeping body position, with less time spent supine when at home that during polysomnography, given multiple factors. These could include less restriction due to leads, changes in bedroom environment and bed size.