Obesity is associated with high rates of gastro-oesophageal reflux, abdominal pain and irritable bowel symptoms, which are not influenced by the use of medications for other conditions such as asthma and high blood pressure, say researchers.
Dr Nicholas Talley, from the Mayo Clinic in Rochester, Minnesota, USA, and colleagues aimed to find out whether the association between obesity and gastro-oesophageal reflux symptoms are caused or influenced by taking medications that may reduce the effectiveness of the lower oesophageal sphincter (LES) – the muscle that prevents stomach acid from entering the oesophagus.
For their study, the researchers examined findings from endoscope examinations of the oesophagus in around 1000 people in Sweden. Each participant's body mass index was calculated and his or her use of medications recorded.
Gastro-oesophageal reflux symptoms were defined as "bothersome heartburn or acid regurgitation".
The team found that 16% of the participants were obese, while 46% were classed as being overweight.
More than 26% of obese patients had oesophagitis (inflammation of the oesophagus), compared with just 9% of participants who were of normal weight.
Furthermore, obesity was significantly associated with gastro-oesophageal reflux symptoms, confirming previous studies. In addition, answers given to an abdominal symptom questionnaire revealed that obese patients were more likely to experience abdominal pain and irritable bowel symptoms.
However, the investigators found no evidence of an association between medications that may relax the LES – such as calcium channel blockers for heart problems and beta agonists for asthma – and gastro-oesophageal reflux symptoms in obese patients.
The researchers conclude in the journal Gut that "reflux symptoms are independently associated with BMI", but that these symptoms in obese individuals do not appear to be caused or influenced by the taking of LES-relaxing medications.
They add that, because obesity is becoming an increasing health problem worldwide, further research into the links between BMI and gastro-oesophageal reflux symptoms is important.