Reassessment of the principal characteristics of gastroesophageal reflux during the recumbent period using integrated actigraphy-acquired information

OBJECTIVES: Characterization of gastroesophageal reflux (GERD) events during the sleep period has been hampered by lack of any patient-friendly technique that allows accurate assessment of sleep duration and awakening time, without confining patients to a sleep laboratory. Our aim was to compare principal reflux characteristics during the upright, recumbent-awake, and recumbent-asleep periods as well as to determine the effect of sleep awakenings on the principal reflux characteristics of the recumbent-asleep period using novel technology that allows integration of recorded actigraphy data into collected pH information.METHODS: Patients with heartburn at least three times a week for the previous 3 months were invited to participate in this study. All participants were evaluated by the demographics and the GERD Symptom Checklist questionnaires. Thereafter, patients underwent ambulatory 24-h esophageal pH monitoring concomitantly with actigraphy. A novel technique was used to superimpose simultaneously recorded raw actigraphy data over pH data, resulting in more accurate information about reflux events during upright, recumbent-awake, recumbent-asleep, and conscious awakening periods as well as the relationship between symptoms and acid reflux events in the aforementioned periods.RESULTS: Thirty-nine subjects (M/F: 26/13, mean age 56.614 years) with an abnormal pH test were enrolled into the study. The recumbent period appeared heterogeneous and was clearly divided into recumbent-awake (123.020.2 min) and recumbent-asleep (485.623.6 min) periods. The percent total time pH4, the mean number of acid reflux events, and the number of symptoms associated with reflux events were significantly greater in the recumbent-awake as compared with the recumbent-asleep period. The mean duration of an acid reflux event was not different among upright, recumbent-awake, and recumbent-asleep periods. However, short-duration reflux events during the sleep period were associated with conscious awakenings as compared with those during sleep (0.740.11 min vs. 1.640.3 min, P0.01).CONCLUSIONS: The recumbent period is divided into recumbent-awake and recumbent-asleep periods. The recumbent-awake period has significantly different principal reflux characteristics than the recumbent-asleep period. Duration of an acid reflux event during the recumbent-asleep period is not uniformly prolonged. Short-duration acid reflux events during the sleep period are likely due to conscious awakenings.