Is NREM-predominant obstructive sleep apnea syndrome a different clinical entity?

Abstract

Background/aim: This study aimed to evaluate whether NREM-predominant obstructive sleep apnea syndrome (OSAS) patients(NREM AHI NREM AHI).Materials and methods: A total of 342 patients (93 females and 249 males) who were admitted to the Sleep Disorders Unit at the GaziUniversity Faculty of Medicine and underwent polysomnography between January 2011 and April 2016 were retrospectively reviewed.Patient data, symptoms related to OSAS, Epworth Sleepiness Scale (ESS) scores, and polysomnographic findings were recorded. Thepatients were divided into two groups according to the apnea–hypopnea index (AHI) as patients with NREM-predominant OSAS andpatients with REM-predominant OSAS.Results: The total AHI in the NREM-predominant group was significantly higher than in the REM-predominant group (P < 0.001). Thepatients with severe OSAS constituted the majority in both groups, and the rate of patients with severe OSAS was significantly higherin the NREM-predominant group than in the REM-predominant group (P < 0.001). Arousal index and sleep time spent under 90%SaO2 was higher in the NREM-predominant group (P = 0.005, P = 0.001), whereas nocturnal mean and minimum O2 saturation valueswere lower in the NREM-predominant group compared to patients with REM-predominant OSAS (P < 0.001, P = 0.013). In evaluatingsystemic disorders, the prevalence of coronary artery disease was significantly higher in the NREM-predominant OSAS group (P