Prevalence and Factors Associated with Rapid Eye Movement-Related Obstructive Sleep Apnea in Patients with Narcolepsy

Data on the prevalence and correlates of rapid eye movement (REM)-related obstructive sleep apnea (REM-OSA) in narcolepsy remains limited. This study aimed to assess the prevalence and independent associated factors with OSA and REM-OSA in patients with narcolepsy, and to compare the distribution of REM-OSA between patients with narcolepsy and matched controls without narcolepsy. This retrospective study of a prospectively collected cohort included 190 adult patients with narcolepsy (narcolepsy type 1 [NT1] = 119, narcolepsy type 2 [NT2] = 71) who underwent polysomnography and multiple sleep latency test at the University Sleep Disorders Center, King Saud University Medical City, between January 2007 and February 2022. REM-OSA was defined as an apnea-hypopnea index (AHI) ≥5, AHI-REM/AHI-non-rapid eye movement (NREM) ≥2, AHI-NREM <8, and REM sleep duration >10.5 minutes. A total of 106 patients with narcolepsy were diagnosed with OSA. A control group of 122 patients with OSA but without narcolepsy, matched by age, sex, AHI, and BMI, was used for comparison. Logistic regression identified independent associated factors with OSA and REM-OSA. OSA was diagnosed in 106 patients with narcolepsy (55.8%). REM-OSA was present in 26.4% of these cases, with a slightly higher prevalence in NT2 (30%) than in NT1 (24%). REM-OSA showed a trend toward higher prevalence in the narcolepsy group compared to controls (26.4% vs 17.2%, OR: 1.73, 95% CI: 0.91-3.27, p = 0.09). Male sex, BMI, and arousal index were independent correlates of OSA among patients with narcolepsy. REM-OSA was independently associated with arousal index and REM sleep duration. OSA and REM-OSA are common in patients with narcolepsy. REM-OSA was more prevalent in the narcolepsy group than in matched controls, suggesting a potential association between narcolepsy and REM-OSA that warrants investigation in larger cohorts.