Night-to-night repeatability of supine-related obstructive sleep apnea.
BACKGROUND
Patients with obstructive sleep apnea (OSA) experience respiratory events with greater frequency and severity while in the supine sleeping position. Postural modification devices (PMDs) prevent supine sleep, although there is a paucity of guidance to help clinicians decide when to use PMDs for their patients. In order for PMDs to treat OSA effectively, patients must experience respiratory events in the supine sleeping position consistently from night to night and must have a low nonsupine apnea and hypopnea index (AHINS).


OBJECTIVE
To document the repeatability of traditionally defined supine predominant OSA on consecutive polysomnography, to determine whether the consistency of the supine-predominant phenotype can be improved by altering the definition of it, and to determine whether a low AHINS is repeatable from night to night.


METHODS
We recruited 75 patients for polysomnography on two separate nights. Patients were classified as having supine OSA on each night on the basis of traditional and novel definitions, and the classification systems used were compared on the basis of agreement from night to night.


RESULTS
The definition of supine OSA with the highest level of agreement from night to night incorporates a supine AHI (AHIS) to AHINS ratio ≥4:1. In addition, agreement exists for males, but there is poor agreement for female patients, regardless of the definition applied. An AHINS <10 events/hour is highly repeatable from night to night.


CONCLUSIONS
Males with an AHIS:AHINS ratio ≥4:1 and an AHINS <10 events/hour represent a consistent supine-predominant OSA phenotype from night to night. This patient group is likely to benefit from treatment with PMD.
1 B. Monash Lung and Sleep, Monash Health, Clayton, Australia.
Simon A
SA
Joosten
Fergal J
FJ
O'Donoghue
Peter D
PD
Rochford
Maree
M
Barnes
Kais
K
Hamza
Thomas J
TJ
Churchward
Philip J
PJ
Berger
Garun S
GS
Hamilton
D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods*; D011379:Prognosis; D012138:Respiratory Therapy / Q000379:methods*; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D016683:Supine Position / Q000502:physiology*
diagnosis; management; sleep-disordered breathing