0474 The Impact of Neck Circumference and Body Mass Index on Upper Airway Collapsibility

Introduction Drug-induced sleep endoscopy (DISE) is the most commonly utilized diagnostic tool for determining sites of upper airway collapse in patients with obstructive sleep apnea (OSA) seeking alternative treatments to continuous positive airway pressure (CPAP). Drug-induced sleep endoscopy with positive airway pressure (DISE-PAP) is a new technique that allows for both the qualitative visualization of upper airway collapse as well as a quantitative measure of collapsibility. In this study, we sought to determine if the anatomic features of neck circumference and body mass index (BMI) impact the degree of upper airway collapsibility, also known as the pharyngeal opening pressure (PhOP), during DISE-PAP. Methods This was a retrospective, consecutive cohort study of adult sleep surgery patients referred to a CPAP-alternatives clinic and evaluated by a single, experienced sleep surgeon at a tertiary care center from July 2021 to September 2023. Inclusion criteria were adults greater than 18 years of age with a history of OSA (apnea hypopnea index > 5) and a history of CPAP-intolerance. All patients underwent DISE-PAP in a standardized fashion as previously described by the senior author. The primary outcome sought to determine the relationship between neck circumference and the degree of upper airway collapsibility (PhOP), while the secondary outcome evaluated the relationship between BMI and PhOP. Results 97 patients were included for neck circumference and 264 patients were included in analysis of BMI. On average, the cohort was middle-aged, obese (BMI 30.3), male (70.5%), White (64.8%), and with moderate-severe obstructive sleep apnea (AHI 33.3). In terms of our primary hypothesis, a mild positive correlation was observed between neck circumference and PhOP (Spearman correlation coefficient = 0.310, p = .002). In regards to our secondary hypothesis, a mild positive correlation was observed between BMI and PhOP (Spearman correlation coefficient = 0.237, p = 0.0001). Conclusion This study found a weak but statistically significant correlation between both neck circumference and BMI and the degree of upper airway collapsibility. These findings contribute to the current understanding of the impact on neck circumference and BMI on OSA. Further research is required to determine the clinical impact of these outcomes in the management of CPAP-intolerant patients. Support (if any)