Estimated respiratory arousal threshold in patients with rapid eye movement obstructive sleep apnea
Tetsuro Hoshino, Ryujiro Sasanabe, Kenta Murotani, Reiko Hori, Mamiko Mano, Atsuhiko Nomura, Noriyuki Konishi, Masayo Baku, Yoshitomo Nishio, Chihiro Kato, Wojciech Kuczyński, Toshiaki Shiomi
Abstract
Abstract Purpose Rapid eye movement (REM) obstructive sleep apnea (OSA) is a prevalent clinical phenotype. However, the literature focusing on the pathophysiology of REM OSA is limited. This study compared the proportion of individuals with a low respiratory arousal threshold between patients with REM and non-REM OSA. Methods REM OSA was defined as having an apnea–hypopnea index (AHI) ≥ 5 and AHI during REM (AHI-REM)/AHI during NREM (AHI-NREM) ≥ 2. REM OSA was sub-divided into REM-predominant OSA and REM-isolated OSA. REM-predominant OSA was defined as satisfying the definition of REM OSA and having an AHI-NREM ≥ 5. REM-isolated OSA was defined as satisfying the definition of REM OSA and having an AHI-NREM < 5. Patients with an AHI-REM/AHI-NREM < 2 were defined as having non-REM OSA. A low respiratory arousal threshold was defined as having 2 or more of the following conditions: AHI < 30 events/h, proportion of hypopnea > 58.3%, and nadir SpO 2 > 82.5%. Results The proportions of individuals with low respiratory arousal thresholds among individuals with REM-predominant OSA and REM-isolated OSA were significantly higher (77.2% and 93.7%, respectively) than that of patients with non-REM OSA (48.6%). This was also true when the analysis was performed according to sex. Conclusion These results indicate that a low respiratory arousal threshold might be an important endotype that contributes to the pathogenesis of REM OSA, especially in REM-isolated OSA.