Physical findings and the risk for obstructive sleep apnea - The importance of oropharyngeal structures

In this study, we hypothesized that anatomic abnormalities of the oropharyn x, particularly narrowing of the airway by the lateral pharyngeal walls, to nsils, and tongue, would be associated with an increased likelihood for obs tructive apnea among patients presenting to a sleep disorders center. To te st this hypothesis, we used data from a cohort of 420 patients presenting t o the Penn Center for Sleep Disorders. Associations between individual vari ables in the clinical evaluation model and sleep apnea as defined by a re-s piratory disturbance index greater than or equal to 15 events per hour were characterized by odds ratios (ORs) with 95% confidence intervals (Cls). Mu ltivariable logistic regression was used to simultaneously estimate ORs for multiple variables and to control for other relevant patient characteristi cs. Results showed that narrowing of the airway by the lateral pharyngeal w alls (OR = 2.5; 95% CI, 1.6-3.9) had the highest association with obstructi ve sleep apnea (OSA) followed by tonsillar enlargement (OR = 2.0; 95% CI, 1 .0-3.8), enlargement of the uvula (OR = 1.9; 95% CI, 1.2-2.9), and tongue e nlargement (OR = 1.8; 95% CI, 1.0-3.1). Low-lying palate, retrognathia, and overjet were not found to be significantly associated with OSA. Controllin g for BMI and neck circumference, only lateral narrowing and enlargement of the tonsils maintained their significant (OR = 2.0 and 2.6, respectively). A subgroup analysis examining differences between male and female subjects showed that no oropharyngeal risk factor achieved significance in women wh ile lateral narrowing was the sole independent risk factor in men. These fi ndings suggest that enlargement of the oropharyngeal soft tissue structures , particularly the lateral pharyngeal walls, is associated with an increase d likelihood of OSA among patients presenting to sleep disorders centers.