[Analysis of upper airway morphology and laryngopharyngeal reflux in obese patients with OSA]

Objective: To investigate the morphological characteristics of upper airway and laryngopharyngeal reflux in obese patients with obstructive sleep apnea (OSA). Methods: A retrospective analysis was performed on the clinical data of 284 adult patients who underwent polysomnography (PSG) from April 2020 to April 2021 in the Department of Otorhinolaryngology, Head and Neck Surgery, Zhongnan Hospital of Wuhan University, including 83 males and 201 females, aged (32.70±7.74) years. Patients were divided into obese group (n=234) and non-obese group (n=50) according to body mass index (BMI). Patients were divided into mild OSA group, moderate OSA group, severe OSA group and extremely severe OSA group by PSG.The results of sleepiness and laryngopharyngeal reflux questionnaire, nasolaryngoscopy and polysomnography were compared in each group. SPSS (version 22.0) software was used in data analysis. Results: Compared with the non-obese OSA group, the lymphoid hyperplasia of tongue root was more heavy in the obese OSA group, and Mueller's maneuver showed that the left-right lateral collapse of the velopharyngeal plane was more serious. Meanwhile, the scores of reflux symtom index (RSI) and reflux finding score (RFS) in the obese OSA group were significantly increased, and the scores of RSI and RFS increased with the increase of OSA severity. The main respiratory events in obese patients with OSA were obstructive hypopnea, their apnea-hypopnea indices(AHI) during REM (AHI_REM) was significantly higher than non-REM (AHI_NREM), and they had lower average blood oxygen saturation. Yet, there was no significant difference in the lowest blood oxygen saturation between the two groups. Conclusions: Our study suggests that lateral pharyngeal wall stenosis in velopharyngeal plane and the lymphoid hyperplasia of tongue root in glossopharyngeal plane occurs more frequently in obese patients with OSA. Laryngopharyngeal reflux is significantly increased in obese patients, and OSA increases laryngopharyngeal reflux in obese patients.