The frequency and properties of REM related obstructive sleep apnea among the patients with mild related obstructive sleep apnea

Introduction: The question if REM related obstructive sleep apnea (OSA) is a specific clinical entity or if it is an early sign of severe sleep disordered breathing as there is high occurrence of REM OSA in mild and moderate cases, recently have attracted the investigators. In this study, we aimed to see the frequency of REM related OSA among patients with mild OSA; and also to evaluate relation between apnea and daytime sleepiness among REM related OSA patients. Materials and Methods: One hundred thirty four patients with mild OSA [Apnea hipopnea index (AHI)= 5-15] among 1267 patients with polysomnography examination at sleep laboratory of Bezmialem University Hospital between 1st August 2010 and 29th February 2012 were retrospectively evaluated. Patients having REM AHI/non-REM AHI >= 2 and non-REM AHI < 15 are considered as REM related OSA. Results: Eighty (59%) of 134 patients with mild OSA were considered as REM related OSA. When REM related OSA and non REM OSA are compared for age, gender, daytime sleepiness, body mass index, neck surround and aditional diseases; mean age of REM related OSA group was found only significantly lower. Number of AHI in REM was over 15 at 87.3% of REM related OSA group and over 30 at 39.3% of them. There was no relation between REM AHI and daytime sleepiness symptom (p= 0.81). Conclusion: We may consider the result of lower mean age in REM related OSA group as a supporting result for early sign of severe sleep disordered breathing. We consider to follow up this group of patients to answer the question about subject.