Apnoea–Hypopnoea Index during Rapid Eye Movement and Non-Rapid Eye Movement Sleep in Obstructive Sleep Apnoea

Abstract

This study investigated the differences in apnoea-hypopnoea index (AHI) during rapid eye movement (REM) sleep (AHI-REM) and AHI during non-REM (NREM) sleep (AHI-NREM) in patients with obstructive sleep apnoea (OSA). Nocturnal polysomnography was performed in 102 Japanese OSA patients and their AHI along with a variety of other factors were retrospectively evaluated. Regardless of the severity of AHI, mean apnoea duration was longer and patients' lowest recorded oxygen saturation measured by pulse oximetry was lower during REM sleep than during NREM sleep. Approximately half of the patients (n = 50) had a higher AHI-NREM than AHI-REM. In subjects with AHI >or= 60 events/h, AHI-NREM was significantly higher than AHI-REM. On multivariate logistic regression, severe AHI >or= 30 events/h was the only predictor of a higher AHI-NREM than AHI-REM. This may indicate that important, but unknown, factors related to the mechanism responsible for the severity of OSA are operative during NREM sleep.

NREM-AHI greater than REM-AHI versus REM-AHI greater than NREM-AHI in patients with obstructive sleep apnea: clinical and polysomnographic features

“…Some researchers find no difference in AHI between REM and NREM sleep [15,34], while others reveal higher AHI in REM than in NREM sleep [35,36]. In the present study, more than half of the patients (54.9%) had a higher NREM-AHI than REM-AHI, which is consistent with the findings in previous studies [15][16][17]. Our study and others [15][16][17] raise the fact that a high prevalence of patients having a higher NREM-AHI than REM-AHI exists in clinical OSA population.…”

“…Similarly, Siddiqui and coworkers reported a higher apnea-hypopnea index (AHI) during NREM sleep (NREM-AHI) than during REM sleep (REM-AHI) in half of OSA patients [16]; in their study, most of the usual predictors for severity of OSA did not discriminate this fact of higher AHI in NREM than REM [16]. Recently, data from Muraki et al shows that approximately half of the patients (49.0%) have a higher NREM-AHI than REM-AHI, and severe AHI≥30 events/h is the only predictor of a higher NREM-AHI than REM-AHI [17]. These observations suggest a high prevalence of patients with a higher NREM-AHI than REM-AHI in the clinical OSA population.…”

Responsiveness of Jaw Motor Activation to Arousals during Sleep in Patients with Obstructive Sleep Apnea Syndrome

“…31 In addition, arousal threshold to respiratory disturbance was higher during REM sleep than NREM sleep since a respiratory event of longer duration and larger amplitude of oxygen desaturation are needed to trigger arousals in REM sleep. [17][18][19]21,29,32,33 In this study, submental muscle activation was needed for scoring arousals during REM sleep, 25 indicating that the motor system is released from active inhibition during arousals scored. Under such conditions, MAS muscles are activated more frequently in relation to an increase in the arousal duration.…”

The Impact of Body Posture and Sleep Stages on Sleep Apnea Severity in Adults

“…13,14,17,21 We could not assess this pattern in our cohort, which was comprised of mainly normal, mild, or moderate OSA patients. However, the reported NREM dominance trend for severe OSA is not surprising, since 75% or more of the TST typically consists of NREM sleep.…”