title: Determinants of Abnormal Supine Reflux in 24-Hour pH Recordings.
abstract: A previous study showed that supine gastroesophageal reflux occurs mainly in the early nighttime period and is greater if the patient retires within 2 hr of a meal. We analyzed 306 consecutive esophageal pH studies between January and July 2003. Ninety-two patients had abnormal supine reflux. The recumbent period was divided into quarters (Q1-Q4) and reflux parameters were calculated for each period. Reflux was maximal in Q1, and decreased progressively from Q1 to Q4 (P<0.001). Median time between evening meal and retiring was no different from that for 44 upright gastroesophageal reflux patients. Patients retiring within 2 hr of a meal had a higher percentage supine reflux time (P=0.012), but no increase in reflux was observed in those retiring within 3 hr. Supine reflux occurs maximally in the early nighttime period. Although not fully explained as a postprandial phenomenon, these patients should avoid going to bed within 3 hr of a meal.
authors.affiliation: Department of Gastroenterology, Hemel Hempstead General Hospital, Hillfield Road, Hemel Hempstead, Herts, HP2 4AD, UK. alistair.king@whht.nhs.uk
authors.forename: Alistair L
authors.initials: AL
authors.lastname: King
authors.forename: Bijay
authors.initials: B
authors.lastname: Baburajan
authors.forename: Terry
authors.initials: T
authors.lastname: Wong
authors.forename: Roy
authors.initials: R
authors.lastname: Anggiansah
authors.forename: Angela
authors.initials: A
authors.lastname: Anggiansah
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D016683:Supine Position / Q000502:physiology*