Effect of Body Mass Index on Upper Airway Obstruction as Revealed by Drug-Induced Sleep Endoscopy in Patients With Sleep-Disordered Breathing

Abstract

Background and Objectives Drug-induced sleep endoscopy (DISE) usefully determines the sites of airway obstruction in patients with sleep-disordered breathing. It is widely accepted that obesity increases obstructive sleep apnea. However, no study has explored how and where obesity causes obstructions. In this study, we described the patterns of upper airway obstruction revealed by DISE in patients of various body mass indices (BMIs) with sleep-disordered breathing.Subjects and Method All subjects had sleep-disordered breathing and underwent DISE. Endoscopic findings at the retropalatal (upper lateral, upper anteroposterior [AP]) and retrolingual (lower lateral, lower AP) levels were graded; obstruction was complete (2), partial (1), or none (0). Subjects with BMI <25 (<25 group), 25≤BMI<30 (25<30 group), and ≥30 kg/m² (>30 group) were compared using a dummy variable; to this end, we employed R ver. 4.0.5.Results For the total of 153 patients reviewed, the mean age was 43.1±12.2 years and the mean BMI was 26.0±3.4 kg/m². At the retropalatal AP level, the DISE grade was significantly higher in the 25<30 group than in the <25 group (<i>p</i>=0.029) but not in the >30 group (<i>p</i>=0.248). At the retropalatal lateral level, significant increases were evident in both of the higher BMI groups (<i>p</i>=0.06 and <i>p</i>=0.024, respectively). No significant relationship was found at the retrolingual level.Conclusion In terms of the retropalatal AP and lateral diameters, a higher BMI is associated with a greater incidence of more severe obstruction.