The Prevalence and Characteristics of Positional Sleep Apnea in Korea

Abstract

Background and Objectives：Obstructive sleep apnea (OSA) patients are classified into positional patients with supine apneahypopnea index (AHI) that is at least twice as high as the non-supine AHI, and non-positional patients with a supine AHI that does not reach double values of the non-supine AHI. We determined the prevalence of positional sleep apnea and compared clinical characteristics between positional and non-positional OSA patients. Subjects and Method：This was a cross-sectional study at a tertiary rhinologic referral center. We evaluated 113 patients whose AHI were over 5 and whose sleep time of supine, nonsupine position were over 15 minutes as a result of overnight polysomnography taken from January 2007 to July 2008. The body position of patients was confirmed with sleep position sensor and direct observation. Results：Positional sleep apnea was seen in 14/22 (63.64%) with mild sleep apnea (AHI, 5 to 15/h), 16/36 (44.44%) with moderate sleep apnea (AHI, 15 to 30/h), 14/55 (25.45%) with severe sleep apnea (AHI, ≥30/h) and over all prevalence of positional sleep apnea in this study is 38.9%. The severity of OSA, weight, waist and waist to hip ratio (WHR) is related to the positional tendency. Conclusion：The result of this study revealed that positional sleep apnea was more common in patients with mild OSA and the positional tendency of OSA patients was affected by central obesity. (Korean J Otorhinolaryngol-Head Neck Surg 2009;52:407-12)