Obese patients have an increased risk of gastro-esophageal reflux disease.
However, the mechanism underlying this association is uncertain.
Dr Anggiansah Sweis and colleagues investigated mechanical effects of obesity on esophageal function increase acid exposure and symptoms.
Height, weight and waist circumference were measured in patients with typical reflux symptoms referred for manometry, and 24 hour ambulatory pH studies.
The research team reported that the symptom severity was assessed by questionnaire.
The association between obesity, esophageal function, acid exposure and reflux symptoms was assessed.
The research team obtained physiological measurements from 582 patients of whom 406 completed symptom questionnaires.
The prevalence of general obesity was greater in women, however more men had abdominal obesity.
|Reflux symptoms increased with acid exposure|
|Alimentary Pharmacology & Therapeutics|
The doctors found that esophageal acid exposure increased with obesity and was associated also with lower esophageal sphincter pressure, reduced abdominal lower esophageal sphincter length and peristaltic dysfunction.
The team showed a negative association of weight and waist circumference with both lower esophageal sphincter pressure, and abdominal lower esophageal sphincter length.
The researchers demonstrated that the effects of increasing weight and waist circumference on esophageal function do not explain increased acid reflux in obese patients.
Instead, independent effects of obesity and esophageal dysfunction on acid exposure were present.
The doctors noted that the reflux symptoms increased with acid exposure, and this association explained increased symptom severity in obese patients.
Dr Sweis' team concluded, "Abdominal obesity is associated with oesophageal dysfunction, increased acid exposure and reflux symptoms."
"However, this analysis does not support the mechanical hypothesis that the effects of obesity on esophageal function are the cause of increased acid exposure in obese patients."