RESUMO
INTRODUCTION: Obesity is a condition that has been associated with gastroesophageal reflux disease (GERD), however, a cause-effect relationship has not been established. AIM: To analyze current evidence evaluating the relationship between obesity and GERD, as well as the impact of hypocaloric diets and bariatric surgery in gastroesophageal reflux symptoms. MATERIAL AND METHODS: An electronic search in the MEDLINE was performed, looking for information published during the past 15 years: Cohort studies, case-control studies, case series and case reports, including the following key words: "heartburn", "reflux", "gerd", "reflux esophagitis", "obesity", "overweight", "diet", "bariatric surgery" were analized. RESULTS: Thirty-one articles were included. These studies were classified according to the diagnostic method of GERD (i.e., manometry, 24-hour pH monitoring, esophageal transit, endoscopy) and type of bariatric surgery: Adjustable gastric banding (AGB), vertical banded gastroplasty (VBG), and Roux-en-Y gastric bypass (RYGB), or anti-reflux procedure. CONCLUSIONS: Most studies suggest that obesity is a condition predisposing to the development of GERD. However, there are no studies that correlate the degree of obesity with the symptoms of reflux. Hypotonic lower esophageal sphincter, ineffective esophageal motility and presence of hiatal hernia are the pathophysiological mechanisms proposed as inductors of gastroesophageal reflux among obese patients. AGB and VBG seem to induce postoperative esophagitis in some patients, but RYGB has shown to be effective to control GERD symptoms. Overweight and obesity do not seem to affect the results of antireflux surgery. The impact of body weight loss on GERD following hypocaloric diets requires further investigation.