Nighttime reflux is primarily an early event.
OBJECTIVE
Our clinical impression gleaned from reading large numbers of ambulatory pH studies is that recumbent reflux episodes mostly occur in the early part of the nighttime period. In this study, we propose to test this hypothesis.


METHODS
A total of 201 consecutive pH studies performed in our laboratory between November 2001 and October 2002 were analyzed. Population characteristics: 75 males and 126 females; mean age, 50.4 yrs (range, 16-88 years). Reflux was defined by a drop in pH to less than 4. Abnormal total recumbent reflux was defined as >1.2% time pH < 4. For patients with abnormal recumbent reflux, the recumbent period was divided into two halves and the reflux time in each period was calculated. In all patients, ingestion of a meal within 2 hours of retiring was also identified.


RESULTS
A total of 59 patients had abnormal recumbent reflux: 24 males and 35 females; mean age, 48.9 years. In patients with abnormal recumbent reflux, acid reflux was significantly more frequent in the first half of the recumbent period compared with the second half (median, 6.3%; vs. 0.3%, respectively; P < 0.001; Wilcoxon signed rank test, two-tailed analysis). Those patients (N = 118) having had a meal within 2 hours of retiring were 2.46 times more likely to develop recumbent reflux than those whose last meal was more than 2 hours earlier (N = 83).


CONCLUSIONS
These results support our hypothesis that nighttime reflux occurs primarily during the first half of the recumbent period. In addition, they reinforce the concept of maintaining control of early nighttime reflux and the importance of counseling patients with nocturnal symptoms against late meals and snacks.
Hila
Amine
A
Department of Gastroenterology and Hepatology, Medical University of South Carolina, Charleston, SC 29425, USA. hila@musc.edu
Castell
Donald O
DO
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002940:Circadian Rhythm / Q000502:physiology*; D005247:Feeding Behavior; D005260:Female; D005500:Follow-Up Studies; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008365:Manometry; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011312:Pressure; D012189:Retrospective Studies; D012307:Risk Factors; D012890:Sleep / Q000502:physiology; D013997:Time Factors