GERD and Obesity: Is the Autonomic Nervous System the Missing Link?

Abstract

Gastroesophageal reflux disease (GERD) is a common chronic condition that not only impairs the quality of life of those who are affected by it but also poses a significant economic burden. It encompasses a wide spectrum of symptoms as a result of gastric content moving into the esophagus. The most common cause of GERD, other than a hiatus hernia, is considered to be transient lower esophageal sphincter relaxation. The lower esophageal sphincter (LES) normally has a higher resting tone than the stomach, thus preventing the reflux of gastric contents into the esophagus. The greater prevalence of GERD and GERD symptoms in obese individuals has generated significant interest in understanding the association between these 2 conditions and the underlying physiological mechanisms. The potential relationship between GERD and obesity and the exact mechanism by which obesity may cause reflux, however, remains uncertain. It has been proposed that patients with GERD have altered autonomic nervous function and, more specifically, have reduced parasympathetic activity. Obese individuals also have shown diminished parasympathetic activity, which may be reversed after weight reduction through exercise, diet control, and bariatric surgery. Given that contraction and relaxation of the LES are vagally mediated, the question that arises is whether the autonomic nervous system is, in fact, the missing link between obesity and GERD. In this article we examine the current evidence and hypothesize that the potential imbalance in sympathovagal stimulation to the LES is a key contributing factor to the increased prevalence of GERD symptoms in obese individuals.

Clinical characteristics associated with esophageal motility function

“…Preserved LES pressure, therefore, plays an important role in protecting against the development of GERD. Several studies have addressed the potential relationship between obesity and GERD, in which obesity affected esophageal motility, especially with altered LES pressure . Patients with morbid obesity have LES dysfunction, even when they are asymptomatic for GERD .…”

“…Several studies have addressed the potential relationship between obesity and GERD, in which obesity affected esophageal motility, especially with altered LES pressure. 5,22,[24][25][26][27] Patients with morbid obesity have LES dysfunction, even when they are asymptomatic for GERD. 22 It has also been reported that almost 50% of those patients have hypomotility of the esophageal body, particularly a lack of effective peristaltic waves.…”

Gastroesophageal Reflux Disease and Sleeve Gastrectomy

“…Obese individuals also have shown diminished parasympathetic activity, which may be reversed after weight loss through exercise, diet control, and bariatric surgery. Given that contraction and relaxation of LES are vagally mediated, the question that arises is whether the autonomous nervous system is in fact the missing link between obesity and GERD [9].…”

“Normal Values of 24H Multichannel Intraluminal Impedance pH-Metry in a Greek Obese Population Based on Montreal Definition of Gerd”

“…As recently published in a case-control study, leptin and ghrelin have a positive association with the presence of Barrett's esophagus [17]. Moreover, it has been implied that the autonomic nervous system may be the missing link between GERD and obesity [18].…”