Year: 2014
Type: dissertation
Study design: Observational Study
Abstract: Obstructive sleep apnea (OSA) is the most common sleep related breathing disorder in adults.Currently, the diagnosis and classification of OSA is based on the number of apnea and hypopnea events or desaturation events per hour, i.e. the apnea hypopnea index (AHI) or the oxygen desaturation index (ODI) detected in polygraphic recordings.Unfortunately, AHI and ODI do not provide detailed information on the severity of individual obstruction events.The aim of this thesis was to investigate morbidity and mortality related to obstructive sleep apnea and to introduce novel diagnostic parameters incorporating information on morphology and duration of obstruction and desaturation events.The most promising of the new parameters was obstruction severity, which incorporates the duration of obstruction and the area of the related desaturation event.These issues were investigated in retrospective studies with ambulatory polygraphic recordings of men (n = 226 1068) referred to the Department of Clinical Neurophysiology at Kuopio University Hospital due to a suspicion of sleep disordered breathing during the years 1993 2007.In addition to re analyzing ambulatory polygraphic recordings, information was collected on morbidity and mortality of patients.Finally, an adjusted AHI parameter connecting AHI and obstruction severity was introduced to allow the use of the American Academy of Sleep Medicine (AASM) Guidelines in the diagnostics of the severity of the disease.The patients with moderate to severe OSA had significantly higher mortality rates as compared to those without OSA.The severity of individual obstruction events showed significant variation between patients having similar AHI.The obstruction severity parameter was found superior to AHI on its own in detecting patients at the highest risk of suffering cardiovascular mortality or morbidity.Adjusted AHI was found to be easily applicable and potentially suitable for clinical use.The novel parameters introduced in this thesis provide important supplementary information to AHI when assessing the severity of OSA and improve the recognition of those patients who carry the highest risk of suffering severe health consequences of OSA.
Author: Anu Muraja‐Murro
Language: English
Subfield: Physiology (medical)
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W3096530867