Multilevel Airway Obstruction Phenotypes in Adult OSA

Abstract

Objective. To describe multilevel phenotypes of airway obstruction identified on drug-induced sleep endoscopy (DISE) in adults.Study Design. Retrospective chart review.Setting. Tertiary care center.Methods. Video recordings of DISE on adult patients were retrospectively scored. A cross-correlation matrix was created to detect significant correlations between DISE findings at anatomical subsites. Three multilevel phenotypes resulted from the matrix: complete collapse at the tongue base with complete collapse at the epiglottis (T2-E2), complete circumferential obstruction at the velum with complete lateral pharyngeal wall collapse at the oropharynx (V2C-O2LPW), and incomplete collapse at the velum with complete collapse due to tonsillar hypertrophy (V0/1-O2T). The mean difference (MD) and 95% confidence interval (CI) were calculated for demographic and polysomnogram metrics of each phenotype compared to all other subjects. Results. Phenotype 1 (T2-E2) (n = 88) had older ages (MD 5.784 years, CI [1.992,9.576]), lower body mass index (BMI) (MD -1.666 kg/m 2 , CI [02.570, −0.762]), and smaller neck circumferences (MD -0.448 in., CI [−9.14, −0.009]) than the other phenotypes. Phenotype 2 (V2C-O2LPW) (n = 25) had higher BMIs (MD 2.813 kg/m 2 , CI [1.362, 4.263]), higher neck circumference (MD 0.714 in., CI [0.004, 1.424]), and higher apnea-hypopnea index (MD 8.252, CI [0.463, 16.041]). Phenotype 3 (V0/1-O2T) (n = 20) had younger ages ). Conclusion.Three distinct multilevel phenotypes of obstruction were identified on DISE, suggesting different anatomic subsites collapse in a nonrandom pattern. The phenotypes appear to represent distinct patient groups and their identification may have implications in terms of pathophysiology and treatment modalities.