Methods: Informed consent was obtained from 80 adult Malay males aged 18-60 years. The first 40 males were patients with OSA [defined as an apnea-hypopnea index > 5/h of sleep] diagnosed with overnight polysomnography. The second group consisted of 40 healthy, non-OSA, Control subjects. Acoustic rhinometry readings were taken from all 80 subjects. Using appropriate software, mean, 3-D, Control and OSA nasopharyngeal airways were computed for each group and subjected to principal components analysis (PCA).
Results: Comparing the 3-D, mean, OSA nasopharyngeal airway with the Control mean, statistical differences were found. Specifically, the first two eigenvalues accounted for 95% of the total shape change (p = 0.0028). Indeed, in a few severe OSA cases the 3-D nasopharyngeal airway differed in morphology from the Control subjects, showing constrictions distal to the nasal valve region and widening in other regions of the nasopharyngeal airway.
Conclusions: These preliminary results indicate that there are shape differences in 3-D nasopharyngeal airway morphology in adult Malay males with and without OSA. The association between nasopharyngeal airway morphology and OSA in this group may play a role in the pathogenesis of OSA in adult Malay males. However, obstruction in the oro-pharyngeal and/or hypo-pharyngeal regions needs to be localized and quantified in further studies.
This study was supported by Universiti Sains Malaysia grant no: 304/PPSP/6131489