Comparison of Clinical Characteristics between Obstructive Sleep Apnea Syndrome and Upper Airway Resistance Syndrome

Eun, Young Gyu; Kim, Sung Wan; Lee, Kun Hee; Cho, Joong Saeng

Abstract

BACKGROUND AND OBJECTIVES
Most of the patients with upper airway resistance syndrome (UARS) remain undiagnosed and are left untreated because of the disagreement with diagnostic criteria of obstructive sleep apnea syndrome (OSAS). The aim of this study is to help understanding UARS through evaluating differences of polysomnographic findings and subjective symptoms between UARS and OSAS.
SUBJECTS AND METHOD
One hundred nineteen patients, who visited for snoring and/or apnea, excessive daytime sleepiness, were included. All patients underwent full night polysomnography (PSG) and performed tests on the 10 cm visual analogue scale (VAS) for 14 symptoms and Epworth sleepiness scale (ESS). PSG results and VAS score were compared between UARS group and OSAS group.
RESULTS
Among 119 patients, 4 patients had simple snoring, 19 patients had UARS and 96 patients had OSAS. Patients with UARS were younger and had lower BMI than OSAS. Apnea index, hypopnea index, respiratory disturbance index, arousal index, portion of slow wave sleep, mean and lowest oxygen saturation were more severe in patients with OSAS than UARS. But subjective symptoms and ESS were similar in both groups.
CONCLUSION
Although significant differences were found in PSG results in patients with UARS and OSAS, complaints and symptoms were similar in both groups. We suggest that diagnosis and treatment for sleep-disordered breathing should not be based solely upon the presence of apnea/hypopnea. We also suggest that more consideration should be given to UARS diagnosis and treatment.