The high dependency of supine position in obstructive sleep apnea

OBJECTIVE: To define the frequency of supine positional obstructive sleep apnea (OSA) in patients diagnosed with OSA and to describe the demographic associations with positional OSA (PO). METHODS: A retrospective study was performed in a total of 3813 patients who underwent full-night polysomnography at the Sleep Disorders Center of the Ataturk Chest Diseases, Thoracic Surgery Education and Research Hospital, Ankara, Turkey between June 2007 and June 2010. A total of 3214 patients diagnosed with OSA were included in the study. Positional OSA was defined as a total AHI more than or equal to 5, and supine AHI/non-supine AHI more than or equal to 2. Characteristics of positional OSA and non-positional OSA groups were compared statistically. RESULTS: Patients classified as positional OSA composed 39.9% of all OSA patients. Positional OSA patients were younger with lower body mass index and their OSA was less severe. CONCLUSION: Positional OSA, which may require different treatment approaches, is not uncommon among OSA patients and should be understood as a different clinical entity.