A79-03 Neural Respiratory Drive and Upper Airway Resistance During Hypopnea in Patients With Obstructive Sleep Apnea

Abstract Background Obstructive hypopnea and apnea events are traditionally characterized by increased respiratory effort, typically assessed using esophageal pressure measurements. However, esophageal pressure can be significantly influenced by changes in lung volume and airflow. Diaphragmatic electromyography (EMGdi), recorded from multipair esophageal electrodes, provides a reliable index of neural respiratory drive and respiratory effort. This study aimed to evaluate neural respiratory drive and upper airway resistance (UAR) during hypopnea events in patients with obstructive sleep apnea (OSA). Methods Twenty patients with OSA (mean AHI: 30.1 ± 20.4 events/hour) underwent overnight polysomnography. Airflow was measured using a pneumotachograph, and esophageal EMGdi signals were recorded to assess respiratory effort. UAR was quantified as the ratio of EMGdi to tidal volume (Vt). A total of 933 obstructive hypopnea events were analyzed. Results Neural respiratory drive during hypopnea events was significantly reduced by approximately 20% compared with pre-event values (p 0.01), while UAR increased by an average of 143% (p 0.01). Both neural respiratory drive and UAR at the end of hypopnea events were typically higher than at event onset, indicating progressive airway narrowing and compensatory neural activation. Conclusion Hypopnea events in OSA are characterized by a decrease in neural respiratory drive accompanied by a marked increase in upper airway resistance. These findings suggest that enhancing neural respiratory drive may represent a potential therapeutic strategy for obstructive sleep apnea. This abstract is funded by: National Natural Science Foundation of China (Grant Number:82070090), Supported by the grant of State Key Laboratory of Respiratory Disease (Grant Number: SKLRD-Z-202413), Guangzhou Municipal Health Commission Major Technical Project Grant 2023C-GX02, Development of a New Oxygen Inhalation Device and Its Clinical Application, SKLRD-L-202401