title: Total duration of apnea and hypopnea events and average desaturation show significant variation in patients with a similar apnea-hypopnea index.
abstract: Obstructive sleep apnea (OSA) is commonly diagnosed based on the apnea-hypopnea index (AHI). Presently, novel indices were introduced for sleep apnea severity: total duration of sleep apnea and hypopnea events (TAHD%) and a combined index including duration and severity of the events (TAHD% × average desaturation). Two hundred and sixty-seven subjects were divided based on their AHI into four categories (normal, mild, moderate, severe OSA). In the most severe cases TAHD% exceeded 70% of the recorded time. This is important as excessive TAHD% may increase mortality and cerebro-vascular complications. Moreover, simultaneous increase in duration and frequency of apnea and hypopnea events leads to a paradoxical situation where AHI cannot increase along severity of the disease. Importantly, the combined index including duration and severity of the events showed significant variation between patients with similar apnea-hypopnea indices. To conclude, the present results suggest that the novel parameters could give supplementary information to AHI when diagnosing the severity of OSA.
authors.affiliation: Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland. Anu.muraja-murro@kuh.fi
authors.forename: A
authors.initials: A
authors.lastname: Muraja-Murro
authors.forename: J
authors.initials: J
authors.lastname: Nurkkala
authors.forename: P
authors.initials: P
authors.lastname: Tiihonen
authors.forename: T
authors.initials: T
authors.lastname: Hukkanen
authors.forename: H
authors.initials: H
authors.lastname: Tuomilehto
authors.forename: J
authors.initials: J
authors.lastname: Kokkarinen
authors.forename: E
authors.initials: E
authors.lastname: Mervaala
authors.forename: J
authors.initials: J
authors.lastname: Töyräs
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology*; D018709:Statistics, Nonparametric