INFLUENCE OF SLEEP ON ALAE-NASI EMG AND NASAL RESISTANCE IN NORMAL MEN

The influence of sleep on the upper airway musculature varies consider ably, with some muscles maintaining their activity at waking levels an d others falling substantially. The influence of sleep on the alae nas i (AN), a dilator muscle of the nasal airway, has been minimally studi ed to date. Thus we determined the effect of non-rapid-eye-movement (N REM) sleep on the AN electromyogram and its relationship to nasal resi stance (Rn) in nine normal supine males. Phasic inspiratory AN activit y decreased from 20 +/- 6 arbitrary units during wakefulness to 5 +/- 1 arbitrary units (P < 0.001) at the onset of stage 2 NREM sleep and r emained unchanged for two subsequent hours of NREM sleep. However, the Rn at the onset of NREM sleep remained similar to awake values (5.7 /- 0.9 cmH2O . l-1 . s) and increased only after 1 h of NREM sleep (8. 6 +/- 1.7 cmH2O . l-1 . s, P < 0.05), thus demonstrating little relati onship to AN activity. We conclude that Rn increases slightly after 1 h of sleep, whereas AN activity decreases at stage 2 sleep onset. Thus AN activity has little influence on Rn during sleep.