Major factors affecting severity of obstructive sleep apnea.

Computed tomography (CT) has become a common method for evaluating obstructive sleep apnea (OSA). The aim of this study was to analyze the relationships between CT parameters and clinical parameters in OSA patients to determine major factors affecting the severity of OSA. The records of 128 consecutive snoring patients (98 males, 30 females) diagnosed with OSA were retrospectively reviewed. Polysomnography was performed for each patient. On CT scans, airway areas were measured at the level of the hard palate, the soft palate, and the base of the tongue. Polysomnographic parameters were compared by gender and age using the Mann-Whitney U test. Pearson's correlation coefficient was used to analyze relationships between variables and the AHI in each age group. The women were significantly older than the men (p < 0.01). The AHI and apnea index were significantly higher in men than in women. Stage 1 sleep and rapid eye movement sleep were more frequent in men than in women. The area at the base of the tongue was significantly smaller in women than in men (p = 0.027). In the 50-60 age group, the AHI was significantly higher in men (41.47 ± 19.67) than in women (17.14 ± 15.63) (p = 0.001). OSA severity varies with age, gender, and upper airway area. The OSA prognosis could be improved by evaluating the major factors and treating OSA patients according to epidemiological characteristics and anatomical structures.