Amelioration of obstructive sleep apnea in REM sleep behavior disorder: implications for the neuromuscular control of OSA.

Abstract

The relationship between REM sleep behavior disorder (RBD) and obstructive sleep apnea (OSA) remains unclear. We aimed to (1) explore the association of REM-related EMG activity (REMREEA) with OSA in RBD patients; (2) compare the severity of OSA between RBD patients with OSA (RBD-OSA) and their age-, sex-, AHI-, and BMI- matched OSA controls. a. Correlation study in consecutive RBD subjects and b. case-control study Sleep laboratory 71 RBD patients in the correlation study and 55 subjects (28 RBD-OSA cases and 27 OSA controls) in the case-control study. N/A METHODS: Polysomnographic assessment to document the sleep architecture, sleep apnea related parameters, and REMREEA. (1) In the correlation study, increased REMREEA was associated with lower severity of OSA in RBD patients, including total AHI (r = -0.263), NREM AHI (r = -0.242), obstructive AHI (r = -0.265), and mean apnea duration (r = -0.353) (P < 0.05). (2) In the case-control study, RBD-OSA patients had lesser severity of sleep apnea parameters than OSA controls in terms of higher nadir SpO(2) (85.7% ± 4.9% vs 80.8% ± 5.9%, P < 0.01), shorter maximum hypopnea duration (53.8 ± 16.7 vs 69.4 ± 22.4 seconds, P < 0.05), and maximum (45.8 ± 20.5 vs 60.8 ± 19.6 sec, P < 0.01) and mean apnea duration (22.3 ± 8.1 vs 26.3 ± 5.8 sec, P < 0.05). Significant interaction effects indicated that the usual REM sleep exacerbation of sleep apneas was seen only in OSA controls but not in RBD subjects. This study demonstrated that excessive EMG activity in RBD might protect patients against severe OSA and suggests this may be a naturalistic model for understanding neuromuscular control of OSA.