title: Gastro-oesophageal reflux in obese subjects: influence of overweight, weight loss and chronic gastric balloon distension.
abstract: BACKGROUND
  Gastro-oesophageal reflux is an obesity-related health risk assumed to improve after weight loss. Prolonged intragastric balloon distension might oppose this. The purpose of the study was to investigate the prevalence of gastro-oesophageal reflux in untreated obese subjects and to study the consequences of weight loss with or without intragastric balloon treatment.
  
  
  METHODS
  Patients participating in a randomized double-blind, sham-controlled trial received balloon or sham treatment for the first 13 weeks. Thereafter, all subjects received a balloon for the remaining year. Twenty-four-hour pH recordings were made at the start, after 13 weeks of balloon or sham treatment, after 26 and 52 weeks of balloon treatment and 13 weeks after balloon removal.
  
  
  RESULTS
  Group-wise, pH data of 42 untreated patients (BMI 43.4 kg/m2) were highly abnormal. On an individual level, 22 subjects (52%) had some evidence of reflux, 17 patients (40%) showed pathological total reflux times and 8 (19%) had combined total, upright and supine reflux with grade B reflux oesophagitis in only one patient. Albeit poorly, oesophageal acid exposure was related to body weight and visceral fat distribution. A reduction in acid reflux was observed in sham-treated weight-losing subjects, whereas in balloon-treated subjects supine reflux and duration of the longest reflux increased. In the second 13-week period, the initially improved pH values worsened by balloon placement in sham-treated subjects. Values in balloon-balloon-treated subjects stabilized. After 52 weeks, acid reflux levelled off at pretreatment values and further improved after balloon removal. At these times, decreased visceral fat masses correlated significantly with diminished oesophageal exposure to acid.
  
  
  CONCLUSIONS
  Obesity predisposed to gastro-oesophageal reflux. Body weight loss and, strikingly, visceral fat loss resulted in improved reflux parameters. Adverse effects on acid reflux by gastric balloon distension wore off over time.
authors.affiliation: Dept. of Gastroenterology and Hepatology, Academic Medical Centre, University of Amsterdam, The Netherlands. e.mathus-vliegen@amc.uva.nl
authors.forename: E M H
authors.initials: EM
authors.lastname: Mathus-Vliegen
authors.forename: G N J
authors.initials: GN
authors.lastname: Tygat
mesh_terms: D000328:Adult; D020878:Device Removal; D003938:Diagnostic Techniques, Digestive System / Q000295:instrumentation; D004311:Double-Blind Method; D016099:Endoscopy, Gastrointestinal; D004942:Esophagitis, Peptic / Q000175:diagnosis / Q000209:etiology; D005260:Female; D015905:Gastric Balloon / Q000009:adverse effects*; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000628:therapy*; D013997:Time Factors; D015431:Weight Loss / Q000502:physiology