Temporal Relationship Between Night-Time Gastroesophageal Reflux Events and Arousals From Sleep

INTRODUCTION: Night-time gastroesophageal reflux (nGER) symptoms are commonly associated with interrupted sleep. Most studies attempting to understand the relationship between sleep, arousal, and nGER events have been performed so using accelerometry; however, this technology is limited in its ability to precisely determine the temporal association between sleep and reflux events. We aimed to examine the temporal relationships between nGER events and arousal/awakening from sleep using high resolution, in-laboratory polysomnography (PSG). METHODS: Individuals between 18 and 70 years who had undergone a gastroscopy within 12 months underwent simultaneous 24-hour pH/impedance monitoring and in-laboratory PSG. The temporal relationship between each nGER event and sleep/arousals/awakenings was determined for each participant. Analyses were limited to the sleep period (between "lights out" and time of final waking). RESULTS: Analyses were conducted on the data from 25 individuals, 64% of whom had nGER episodes (5 +/- 5 events per person, range 1-18) and 64% of whom had obstructive sleep apnea (OSA, mean apnea-hypopnea index 20 +/- 11 events/hr, range 6-44). There were no differences in PSG-determined sleep duration, sleep efficiency, sleep architecture, arousals/awakenings, or sleep apnea severity between those with nGER and those without. Most nGER events (82%) occurred during a PSG epoch that had been classified as wake. Arousals/awakenings preceded almost all events (73/76), whereas fewer had an arousal/awakening after the event (15/76). DISCUSSION: As opposed to what is typically assumed, nGER does not seem to cause arousal from sleep, but rather arousal from sleep predisposes to nGER.