P154 Upper Airway Sensation in Obstructive Sleep Apnea - A Systematic Review and Meta-Analysis to Inform Pathogenesis, Treatment and Future Research

Upper airway sensory impairment may contribute to obstructive sleep apnea (OSA) for certain patients. However, the type of sensory impairment and its role in OSA pathogenesis remain unclear. This study aimed to: (1) evaluate methods of upper airway sensory testing in the OSA literature, (2) compare upper airway sensation in people with and without OSA and (3) investigate the relationship between OSA severity and upper airway sensory impairment. Methods Electronic databases were searched up to February 2020 for studies reporting methods of upper airway sensory testing in people with OSA (n=3,819). From the selected studies (n=38), information on the type of sensation, testing methods, validity and reliability were extracted. Meta-analyses were performed on case-controlled studies and studies reporting correlations between upper airway sensation and OSA severity. Results Seven types of upper airway sensation were reported: olfactory, gustatory, chemical, tactile, vibratory, thermal and neuro-sensation. Methods of upper airway sensory testing varied. No tests were validated or assessed for reliability in OSA populations. People with OSA had impaired sensation on airflow (p<0.001), chemical (p<0.001), gustatory (p=0.01), olfactory (p=0.04) and tactile (p<0.001) tests. Upper airway sensory impairment correlated with OSA severity (p<0.001). Conclusions People with OSA demonstrated impaired upper airway sensation, which related to increasing OSA severity. The extent to which upper airway sensation was impaired varied across testing methods. The findings suggest that development of valid and reliable upper airway sensory tests, that relate to upper airway function in people with OSA, are necessary for future clinical and research practices.