TY - JOUR T1 - Assessment of Upper-Airway Configuration in Obstructive Sleep Apnea Syndrome With Computed Tomography Imaging During Müller Maneuver JF - Respiratory Care SP - 1651 LP - 1658 DO - 10.4187/respcare.04669 VL - 61 IS - 12 AU - Jie-Feng Huang AU - Gong-Ping Chen AU - Bi-Ying Wang AU - Han-Sheng Xie AU - Jian-Ming Zhao AU - Li-Hua Wu AU - Li-Da Chen AU - Qi-Chang Lin Y1 - 2016/12/01 UR - http://rc.rcjournal.com/content/61/12/1651.abstract N2 - BACKGROUND: The purpose of this observational study was to investigate the relationship between upper-airway configuration assessed by CT imaging during the Müller maneuver state and the severity of obstructive sleep apnea syndrome (OSAS).METHODS: A total of 358 snoring subjects who underwent standard polysomnography and upper-airway configuration by using CT imaging were enrolled. According to the apnea-hypopnea index (AHI), subjects were classified into 4 groups: snoring group (simple snoring), AHI < 5; mild OSAS, 5 ≤ AHI < 15; moderate OSAS, 15 ≤ AHI < 30; and severe OSAS, AHI ≥ 30. We also divided the upper airway into 3 parts, named the nasopharynx, oropharynx, and hypopharynx, from the CT scan and evaluated the minimal cross-sectional area (mCSA) and the shape of each airway level and calculated upper-airway length and distance from mandibular plane to hyoid bone (MPH).RESULTS: Multivariate logistic stepwise regression analysis identified body mass index (BMI), mCSA of nasopharynx, upper-airway length, and MPH as risk factors for the severity of OSAS. When subdivided for BMI and sex, upper-airway length was a risk factor for OSAS in non-obese (BMI < 27 kg/m2) and male subjects, and MPH was a risk factor only in obese (BMI ≥ 27 kg/m2) subjects. Meanwhile, mCSA of nasopharynx was significantly associated with the severity of OSAS independent of BMI.CONCLUSIONS: Subjects with severe OSAS have more significant abnormalities of the upper airway. Obesity, mCSA of nasopharynx, upper-airway length, and MPH may contribute to the severity of OSAS. Obesity and sex should be taken into account when evaluating the abnormalities of upper-airway anatomy in snorers and patients with OSAS. ER -