Study objective: To determine the role of craniofacial risk factors in increasing apneic activity between nonobese and obese habitual snorers.
Setting: Care-seeking volunteers identified through advertisements, and referral-based volunteers from two sleep centers serving the greater Cleveland area.
Patients: The study included 142 habitual snorers (mean±SD, 45.5±10.6 years, 68% men; 20% African-Americans)
Measurements and results: Apneic activity was determined using unattended home sleep monitoring to assess the respiratory disturbance index (RDI). Independent variables included body mass index, cranial index, facial index, and 13 anatomic variables (lateral and frontal cephalometric radiographs were used to characterize craniofacial hard and soft tissues). A linear regression model explained approximately 54% and 53% of the variation in RDI (log transformed) scores for the nonobese and obese groups, respectively. The largest predictor of RDI in the nonobese group was tongue length, followed by alignment of the middle cranial fossa, and age. In the obese group, the largest predictor of RDI was hyoid to mandibular plane, followed by tongue length.
Conclusions: Measurements of soft tissues of the oropharynx (especially the tongue) are more closely associated with increased apneic activity. In addition, the hard tissue anatomic limits of the oropharynx may place nonobese individuals in the at-risk group. Therefore, anatomic relationships that are temporally stable may be useful to predict apneic activity in later years.