The impact of obesity on oesophageal acid exposure time on and off proton pump inhibitor therapy.
BACKGROUND
Obesity is associated with increased oesophageal acid exposure time (AET) in patients with gastro-oesophageal reflux (GER), and may decrease the effects of proton pump inhibitors (PPIs).


OBJECTIVE
To evaluate the effects of increased body mass on the ability of PPI therapy to decrease AET in patients with reflux symptoms.


METHODS
Acid exposure time profiles collected from adult patients using wireless pH-metry while on or off PPI therapy was retrospectively reviewed. Patients were separated into five body mass index (BMI) categories as defined by the World Health Organization. A multivariable logistic regression evaluated the association between abnormal AET and BMI groups while controlling for age, gender and pH capsule placement methods.


RESULTS
The study group comprised 968 patients with 336 (34.7%) studied on a PPI and 632 (65.3%) studied off PPI therapy. AET (total greater than 5.3%) was found more frequently in the overweight (67%) and obese classes (74-80%) compared to those who were normal weight (40%) while off acid-suppressing medications (P < 0.001). No significant differences were found between these groups when studied on acid-suppressing medications, and the proportion of patients with abnormal AET across BMI classes was similar regardless of taking a PPI either once or twice daily.


CONCLUSIONS
This is the largest study to report on the relationship between BMI and oesophageal acid exposure time in patients with GER on and off PPI therapy. We conclude that obesity is related to increased acid exposure time, but with no significant difference in acid exposure time among different weight-based groups when taking a once or twice-daily PPI.
Division of Gastroenterology and Hepatology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA.
S L
SL
Shah
Division of Gastroenterology and Hepatology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA.
B E
BE
Lacy
Division of Gastroenterology and Hepatology, Mayo Clinic, Scottsdale, AZ, USA.
J K
JK
DiBaise
Division of Gastroenterology and Hepatology, Mayo Clinic, Scottsdale, AZ, USA.
M F
MF
Vela
Division of Gastroenterology and Hepatology, Mayo Clinic, Scottsdale, AZ, USA.
M D
MD
Crowell
D000328:Adult; D000368:Aged; D015992:Body Mass Index; D050782:Esophageal pH Monitoring; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D054328:Proton Pump Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D012189:Retrospective Studies; D013997:Time Factors
D054328:Proton Pump Inhibitors