CT comparison of primary snoring and obstructive sleep apnea syndrome: role of pharyngeal narrowing ratio and soft palate-tongue contact in awake patient

Soft palate-tongue contact and automatically calculated pharyngeal narrowing ratio (PNR), defined as a ratio between the airway cross-section at the hard palate level and the narrowest cross-section from the hard palate to the epiglottis, could assist in earlier identification of potential obstructive sleep apnea syndrome (OSA) patients even on awake individuals. Parameters were studied on carotid CTA images from 67 consecutively included awake Caucasians who were later classified by second independent physician into the primary snorers (SNORE, n = 34) or obstructive sleep apnea syndrome patient (OSA, n = 33) group according to the clinical examination, laboratory testing and a full-night video polysomnography (PSG) in the sleep laboratory. Imaging and clinical data were statistically compared between groups. The odd’s ratio calculation showed a 2.95 (P = 0.0354) higher risk for OSA development in snoring person with a PNR greater than 8.6. The loose-contact subgroup among OSA patients showed significantly (P = 0.002) higher values of AHI in contrast to the in-contact subgroup.