The effect of unilateral and bilateral nasal obstruction on snoring and sleep apnea.

The purpose of this study was to compare apnea and snoring in patients with different patterns of nasal resistance: normal, high unilateral, and high bilateral. The authors examined 683 unselected patients referred for evaluation of snoring and possible sleep apnea. All patients had determination of nasal resistance (performed during wakefulness in the seated posture) and nocturnal polysomnography including quantitative measurement of snoring. Analysis of variance showed no significant difference in apnea and snoring indices among the three nasal resistance groups (normal, high unilateral, and high bilateral). Furthermore, there was no significant difference in the frequency of patients with different severity of apnea and snoring among the three groups. It is concluded that 1. unilateral and bilateral elevation of nasal resistance may lead to equally severe snoring or apnea; 2. there is no direct relationship between awake seated nasal resistance measurement and sleep disordered breathing; and 3. measurements of supine nasal resistance during sleep may be required to elucidate the relationship between sleep-disordered breathing and nasal obstruction.