Clinical Risk Factors for Sleep Apnea in a Korean Sleep Clinic

Background: Sleep apnea is a common sleep disorder. Since polysomnography is essential for the diagnosis of sleep apnea, patient screening or selection is an important issue in the sleep clinic. The purpose of this study was to investigate the clinical risk factors of sleep apnea in a representative sleep clinic in South Korea. Methods: The medical records of the 7,559 adult patients who visited the sleep clinic from 2009 to 2018 were reviewed. We investigated the demographic data and the results of the sleep questionnaires and polysomnography to determine clinical risk factors of sleep apnea for patients at the sleep clinic. Apnea-hypopnea index over 15 was regarded as clinically significant sleep apnea. Results: A total of 4,581 patients were finally analyzed. In order of significance, age (odds ratio [OR]=1.224 from 50 to 64, p=0.027; OR=1.858 in 65 or more, p<0.001), sex (male) (OR=5.900, p<0.001), body mass index (OR=2.833 from 25 to 29.9 kg/m 2 , p<0.001; OR=9.388 over 30 kg/m 2 , p<0.001) and hypertension (OR=1.537, p<0.001) were independent risk factors of sleep apnea. Conclusions: In South Korea, it is necessary to specify the risk factors of sleep apnea according to the health related characteristics of Koreans. Further research to develop new instruments for screening sleep apnea in Korean sleep clinics is needed.