Comparison between tongue base and soft palate obstruction in obstructive sleep apnea.

CONCLUSIONS

In obstructive sleep apnea syndrome (OSAS), respiratory disturbances are more serious in tongue base-associated obstructions (TBOs) than in soft palate-associated obstructions (SPOs), and the proportion of TBO was predicted by average duration of apnea and hypopnea, and inversely by percentage time of snoring.

OBJECTIVE

To compare the polysomnographic characteristics of two main obstruction sites of OSAS, the soft palate and tongue base, and to identify those variables correlated with tongue base obstructions in patients with OSAS.

PATIENTS AND

METHODS

Thirty-one patients (28 men and 3 women) with OSAS were enrolled in this study. To identify airway obstruction levels upper airway pressure manometry was applied during polysomnography. Airway obstructions were categorized as SPO and TBO by observing pressure patterns. All analyses of events were performed in the supine position.

RESULTS

Average duration of apnea and hypopnea, percentage of apnea among apnea-hypopneas, average O(2) desaturation, and percentage of event-related arousals were significantly higher in TBOs compared with SPOs (all p<0.05). The percentage of TBO among total obstructions (TBO%) was independently associated with average duration of apnea and hypopnea (=0.38, p<0.05) and percentage time of snoring (=-0.44, p<0.01) (adjusted R(2)=30%, p<0.01).