Association of rapid eye movement sleep behavior disorder with sleep-disordered breathing in Parkinson's disease

Rapid eye movement (REM) sleep behavior disorder (RBD) and sleep-disordered breathing (SDB) are two major sleep disturbances observed in patients with Parkinson's disease (PD). However, prior studies exploring the clinical correlations between RBD and SDB in PD have been limited. We aimed to investigate the relationship between RBD and SDB in PD using a case-control study.

A total of 46 PD patients with Hoehn-Yahr stages ranging from 1 to 3 participated in the present study. Participants underwent polysomnography to diagnose the presence of RBD and SDB, and were classified into groups, accordingly. SDB was defined as an apnea-hypopnea index greater than 5. Comparison of clinical and sleep-respiratory parameters was performed among them.

SDB was more frequent in the RBD group than in the non-RBD group (51.4% vs 9.1%, p = 0.016). PD patients with RBD had significantly reduced mean SaO2 and more severe sleep apnea-related parameters during total sleep and non-REM sleep in comparison with non-RBD PD patients. However, there were no differences on the REM-related apnea/hypopnea variables between participants with and without RBD (p > 0.05). Both the frequency of RBD and RBD screening questionnaire (RBDSQ) scores were higher in the participants with SDB than in the participants without SDB (p <0.05). Furthermore, a significant negative correlation was found between RBDSQ and mean SaO2 in all participants.

In PD patients, SDB is more frequent and more severe in patients with RBD than in patients without, and RBD increases the risk of hypoxemia during sleep.