Rapid eye movement related obstructive sleep apnea: Where do we stand?

Rapid eye movement (REM) related obstructive sleep apnea (OSA) is defined by the presence of episodes of apnea or hypopnea predominantly or exclusively during REM sleep. Epidemiology of this disorder shows a complex interaction with age, sex, and body mass index. The prevalence is variable and depends on the criteria used to define this disorder. Moreover, the clinical significance of this entity remains poorly defined. However, episodes of apnea or hypopnea encountered during REM sleep are longer and are associated with a more profound drop in oxygen saturation than non-REM sleep. Likewise, this disorder may be independently associated with hypertension and poor glycemic control. More importantly, positive airway pressure therapy as currently prescribed may not treat the majority of apnea episodes during REM sleep. The treatment is further complicated by the different definitions used for the diagnosis of this disorder and the lack of consensus if patients with this diagnosis should be treated if their overall apnea-hypopnea index does not meet the threshold for the clinical diagnosis of OSA. The definition and treatment used for the diagnosis and management of REM-related OSA needs to be standardized. Moreover, a consensus needs to be developed as to whether patients with this disorder should be treated if their overall apnea-hypopnea index does not meet the threshold for the clinical diagnosis of OSA. Further investigation may help answer if this disorder is independently associated with neurocognitive and cardiometabolic adverse outcomes and help guide the therapeutic approach.