title: Length of Individual Apnea Events Is Increased by Supine Position and Modulated by Severity of Obstructive Sleep Apnea.
abstract: Positional obstructive sleep apnea (OSA) is common among OSA patients. In severe OSA, the obstruction events are longer in supine compared to nonsupine positions. Corresponding scientific information on mild and moderate OSA is lacking. We studied whether individual obstruction and desaturation event severity is increased in supine position in all OSA severity categories and whether the severity of individual events is linked to OSA severity categories. Polygraphic recordings of 2026 patients were retrospectively analyzed. The individual apnea, and hypopnea durations and desaturation event depth, duration, and area of 526 included patients were compared between supine and nonsupine positions in different OSA severity categories. Apnea events were 6.3%, 12.5%, and 11.1% longer (p < 0.001) in supine compared to nonsupine position in mild, moderate, and severe OSA categories, respectively. In moderate and severe OSA categories desaturation areas were 5.7% and 25.5% larger (p < 0.001) in supine position. In both positions the individual event severity was elevated along increasing OSA severity category (p < 0.05). Supine position elevates apnea duration in all and desaturation area in moderate and severe OSA severity categories. This might be more hazardous for supine OSA patients and therefore, estimation of clinical severity of OSA should incorporate also information about individual event characteristics besides AHI.
authors.affiliation: Department of Clinical Neurophysiology, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland; Department of Clinical Neurophysiology, Seinäjoki Central Hospital, Hanneksenrinne 7, 60220 Seinäjoki, Finland; Department of Applied Physics, University of Eastern Finland, Yliopistonranta 1, 70211 Kuopio, Finland.
authors.forename: Timo
authors.identifier: 0000-0003-4017-821X
authors.initials: T
authors.lastname: Leppänen
authors.affiliation: Department of Clinical Neurophysiology, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland; Department of Applied Physics, University of Eastern Finland, Yliopistonranta 1, 70211 Kuopio, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Töyräs
authors.affiliation: Department of Clinical Neurophysiology, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland; Institute of Clinical Medicine, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1, 70211 Kuopio, Finland.
authors.forename: Anu
authors.initials: A
authors.lastname: Muraja-Murro
authors.affiliation: Department of Clinical Neurophysiology, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland; Institute of Clinical Medicine, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1, 70211 Kuopio, Finland.
authors.forename: Salla
authors.initials: S
authors.lastname: Kupari
authors.affiliation: Department of Clinical Neurophysiology, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Tiihonen
authors.affiliation: Department of Clinical Neurophysiology, Kuopio University Hospital, Puijonlaaksontie 2, 70210 Kuopio, Finland; Institute of Clinical Medicine, Faculty of Health Sciences, University of Eastern Finland, Yliopistonranta 1, 70211 Kuopio, Finland.
authors.forename: Esa
authors.initials: E
authors.lastname: Mervaala
authors.affiliation: Department of Clinical Neurophysiology, Seinäjoki Central Hospital, Hanneksenrinne 7, 60220 Seinäjoki, Finland; Department of Applied Physics, University of Eastern Finland, Yliopistonranta 1, 70211 Kuopio, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Kulkas