title: Characteristics of nighttime reflux assessed using multichannel intraluminal impedance pH monitoring and a portable electroencephalograph.
abstract: Gastroesophageal reflux disease (GERD) is strongly associated with sleep disturbances. Although the mechanisms of this association have not been fully elucidated, nighttime reflux plays a central role. However, the detailed characteristics of nighttime reflux occurring during sleep are unknown. The aim of the present study was to examine the characteristics and prevalence of nighttime reflux in the natural sleep environment of GERD patients. Seventeen patients experiencing daily moderate-to-severe heartburn and/or regurgitation were studied using multichannel intraluminal impedance pH monitoring and electroencephalography off-proton pump inhibitor treatment. Nighttime reflux was divided based on reflux type (liquid or gas), acidity (acidic, weakly acidic, or alkaline) and extent (distal only or proximal migration) according to the standard criteria. Nighttime phases were divided as follows: recumbent-awake before falling asleep, nonrapid eye movement, rapid eye movement, awakening from sleep, and post-awakening in the morning. Among 184 nighttime refluxes, 43 (23%) occurred during recumbent-awake before falling asleep, 28 (15%) during nonrapid eye movement, 14 (8%) during rapid eye movement, 86 (46%) during awakening from sleep, and 13 (7%) during post-awakening in the morning. Liquid reflux was more common in awakening during sleep (92%), nonrapid eye movement (100%), and rapid eye movement (100%) compared with awakening before falling asleep (68%). The prevalence of proximal migration was significantly lower in nonrapid eye movement and rapid eye movement than in the other phases. There were no differences in acidity and bolus clearance time among the phases. Thirteen (65%) of 20 events with GERD symptoms had nighttime reflux, suggesting that only 7.1% (13 of 184) of nighttime refluxes were symptomatic. Nighttime reflux was observed in 48 (11%) of 425 awakening episodes during sleep. Different reflux patterns at each phase during nighttime might explain the pathogenesis of GERD and its related sleep disturbances.
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujiwara
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kohata
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakahara
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tanigawa
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yamagami
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Shiba
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tominaga
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Arakawa
mesh_terms: D000328:Adult; D000368:Aged; D002940:Circadian Rhythm; D017097:Electric Impedance; D004569:Electroencephalography / Q000379:methods*; D050782:Esophageal pH Monitoring / Q000379:methods*; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000175:diagnosis* / Q000209:etiology
keywords: gastroesophageal reflux disease; impedance pH monitoring; nighttime reflux; sleep