Evaluation of Eustachian Tube Function and Acid Reflux With Site of Obstruction in Obstructive Sleep Apnea

Objectives: Obstructive sleep apnea (OSA) is a multi-level airway disease, and the specific site of obstruction may influence associated conditions such as eustachian tube dysfunction (ETD) and gastroesophageal reflux disease (GERD). This study aimed to explore the relationship between OSA, ETD, acid reflux, and the anatomical site of obstruction. Methods: Participants were assessed using validated questionnaires for OSA, ETD, and reflux symptoms. The site of upper airway collapse was determined objectively using apneagraphy or sleep MRI. Acid reflux symptoms were evaluated using a standardized reflux symptom questionnaire, and 24-hour pH monitoring was done when indicated. ETD was assessed both subjectively and objectively through the Toynbee maneuver. Results: Sixty-three individuals completed the evaluation. The mean age was 40.4 years, and the mean BMI was 28.1 kg/m<sup>2</sup>. Retroglossal obstruction was observed in 76.1% (48/63), while 23.9% (15/63) had retropalatal obstruction. ETD was diagnosed in 53% of participants, and GERD in 38% by objective testing. A statistically significant association was found between retroglossal collapse and complete ETD (<i>p</i>=0.02). However, no significant link was noted between the obstruction site and laryngopharyngeal reflux or partial ETD. Additionally, salivary pepsin levels showed no correlation with reflux (<i>p</i>=0.412). Conclusions: OSA is frequently accompanied by ETD and GERD. Notably, retroglossal obstruction appears to be significantly associated with complete ETD, suggesting a potential site-specific impact. These findings underscore the importance of anatomical localization in understanding OSA-related comorbidities and warrant further investigation in larger multicenter studies.