Research Design A randomized, placebo-controlled, double-blind, crossover trial (1-week wash out period) comparing 1 night of 5 mg Lemborexant to placebo administered before sleep.~Research Methodology Participants A total of 20 moderate to severe OSA patients with low arousal threshold are randomized 1:1 to either Lemborexant or placebo. The participants will complete two overnight in-laboratory polysomnography (1-week washout), with esophageal pressure catheter placement and standard polysomnography monitoring. Next-morning sleepiness and alertness will also be assessed using Stanford Sleepiness Scale Questionnaire and OSLER test, respectively.~Inclusion criteria~Eligible, healthy individuals with all the followings:~Untreated OSA patient 18 - 65 years of age~AHI ≥15 events/h of sleep~Low arousal threshold~Study protocol All patients who were previously diagnosed with moderate to severe obstructive sleep apnea from baseline polysomnography with a low arousal threshold will be enrolled.~The patients will be subsequently randomized 1:1 to one of the two treatment sequences. Participants will complete two overnight sleep studies and cross-over with 1-week wash-out period. Patients will receive either Lemborexant 5 mg per day or placebo prior 5 minutes before lights-out.~During this 2-night polysomnography, sleep parameters will be analyzed including AHI, arousal threshold, mean and nadir oxygen indices, sleep latency, sleep efficiency, wake after sleep onset (WASO), and percentage of time spent in NREM, stage 1-3 and REM stage. The Stanford Sleepiness Scale Questionnaire to define sleepiness and OSLER test to define vigilance will be obtained on the following morning.
The goal of this randomized, placebo-controlled, double-blind, crossover trial (1-week wash out period) is to compare 1 night of 5 mg Lemborexant to placebo administered before sleep in 20 moderate to severe OSA patients with low arousal threshold~The main questions it aims to answer are:~The effect of Lemborexant on apnea/hypopnea index (AHI) in moderate-to-severe OSA patients with low arousal threshold.~The effect of Lemborexant on the following parameters in moderate-to-severe OSA patients with low arousal threshold.~Arousal threshold~Mean and nadir oxygen saturation~Sleep latency~Sleep efficiency~Wake after sleep onset (WASO)~Percentage of time spent in NREM stage 1-3 and REM stage~Stanford Sleepiness Scale Questionnaire in the morning~The Oxford Sleep Resistance Test (OSLER) test~Participants will~complete two overnight in-laboratory polysomnography (1-week washout), with esophageal pressure catheter placement and standard polysomnography monitoring~complete the Stanford Sleepiness Scale Questionnaire and OSLER test in the morning of the two overnight test~Researchers will compare with the placebo group to see if there is a difference in AHI