Gastroesophageal reflux disease and obesity.

TL;DR: The pathophysiology of GERD in morbidly obese patients might differ from that of nonobese patients, suggesting the need for a different therapeutic approach, and presurgical factors not mentioned in the review are the absence or presence of obesity.

Abstract: Gastroesophageal reflux—the retrograde movement of gastric contents through the lower esophageal sphincter (LES)—is a common, normal phenomenon that may or may not produce symptoms. Causes of this reflux include “an incompetent LES, transient relaxation of the LES and inadequate clearance of acid from the distal esophagus.” With increasing frequency, practicing physicians are seeing patients with symptoms of “gastroesophageal reflux disease (GERD): heartburn, acid regurgitation, noncardiac chest pain, and dysphagia.” Proton pump inhibitors and H2 blockers are mainstays of treatment, and additional treatment options include mucoprotective substances, antacids, and changes in lifestyle and eating habits. When medical management has been ineffective, consideration is given to surgery as a means of improving the competency of the LES. The most common operation currently is Nissan fundoplication, done either laproscopically or by an open procedure. A review, “Nissen Fundoplication and GastrointestinalRelated Complications: A Guide for the Primary Care Physician,” appears in this issue of the Southern Medical Journal. In the introductory remarks of this well-written article, the authors list “the presurgical factors that are associated with a successful outcome of a Nissen fundoplication done for GERD: typical symptoms of GERD, good response to medical therapy, abnormal 24 hour pH monitoring, and the absence of complicated disease.” They go on to describe the problems that can arise after an unsuccessful procedure. These include “persistent recurrent gastrointestinal reflux, dysphagia, gas-bloat syndrome and diarrhea/flatulence.” The pathophysiology, diagnosis, and management of each of these conditions are described. This provides valuable information for the primary care physician faced with a patient with an unfortunate surgical result. One of the presurgical factors not mentioned in the review is the absence or presence of obesity. In an attempt to better understand the pathophysiology of GERD in morbidly obese patients, Herbella et al compared GERD patients with a body mass index (BMI) 35 with those with a BMI 35 with respect to lower esophageal sphincter profile, esophageal body function and esophageal acid exposure. Their data showed that: “(a) BMI was independently associated to the severity of GERD; and (b) in most morbidly obese patients with GERD, reflux occurred despite normal or hypertensive esophageal motility.” They concluded that the pathophysiology of GERD in morbidly obese patients might differ from that of nonobese patients, suggesting the need for a different therapeutic approach. In a somewhat similar study, Ayazi et al quantified the association between BMI, esophageal acid exposure, and LES status in a group of 1,659 patients referred for assessment of GERD symptoms. Comparing data from 24-hour pH monitoring off medication and esophageal manometry, they concluded that “an increase in body mass index was associated with an increase in esophageal acid exposure.” In a further attempt to understand the relationship between GERD and obesity, a group from The Chinese University evaluated the function of the lower esophageal sphincter in morbidly obese patients without GERD. They found “an increase in transient lower esophageal sphincter relaxation and in acid reflux during the postprandial period” in their patients and concluded that these may be early events in the pathogenesis of obesity-related GERD. Given from these studies that obesity is a significant etiologic factor in the development of GERD, attention can be turned to its affect on the outcome of antireflux procedures. Perez et al studied a group of 224 patients who had undergone antireflux operations for GERD. The majority had laproscopic Nissen fundoplications, but 37 had Belsey IV transthoracic procedures. These latter operations were done in obese patients because of the perceived better surgical exposure. The authors’ conclusion was: