Potential role of the cannabinoid receptor CB in the pathogenesis of erosive and non-erosive gastro-oesophageal reflux disease

Association of Cannabis Use with Complications Among Patients with Gastroesophageal Reflux Disease: Insights from National Inpatient Sample

Background/Objective: Cannabis, one of the most widely used recreational drug in the United States, has had a significant surge in usage following its legalization in 1996. In recent years, there has been research into the physiological effects of cannabis on the gastrointestinal (GI) system. Our study aims to systematically examine the association between cannabis use and complications of gastroesophageal reflux disease (GERD). Materials and Methods: We queried the 2016-2020 National Inpatient Sample database to identify patient encounters with GERD. Patients with eosinophilic esophagitis or missing demographics were excluded. We compared patient demographics, comorbidities, and complications among cannabis users and nonusers. Multivariate logistic regression analysis was used to investigate the relationship between cannabis use and complications of GERD. Results: A total of 27.2 million patient encounters were included in the analysis, out of which 507,190 were cannabis users. Majority of the cannabis users were aged between 45-64 years (46.6%), males (57.4%), White (63.84%), and belonged to the lowest income quartile (40.6%). Cannabis users demonstrated a higher prevalence of esophagitis compared to nonusers (6.11% vs. 3.23%, p<0.001). However, they exhibited a lower rates of esophageal stricture (0.6% vs. 0.8%, p<0.001) and esophageal cancer (0.2% vs. 0.24%, p<0.001). After adjusting for confounding factors, cannabis users were noted to have higher odds of esophagitis (adjusted odds ratio [aOR]: 1.34, 95% confidence interval [CI]: 1.30-1.39, p<0.001). A lower odds of esophageal stricture (aOR: 0.88, 95% CI: 0.81-0.96, p=0.02) and esophageal cancer (aOR: 0.48,95% CI: 0.42-0.57, p<0.001) were noted. Conclusion: Our cross-sectional study using the nationally available database indicates an association between cannabis use and higher odds of esophagitis, along with lower odds of esophageal stricture and cancer. While these findings suggest a potential relationship between cannabis use and esophageal complications, it is limited in establishing causality. Therefore, further long-term studies are warranted to understand the mechanism behind this association and to determine if cannabis use has an impact on esophagus.

Palmitoylethanolamide (PEA) for Prevention of Gastroesophageal Inflammation: Insights from In Vitro Models

Gastroesophageal reflux disease (GERD) is a digestive disorder that can lead to chronic mucosal damage, causing esophagitis, Barrett's esophagus and esophageal cancer. GERD currently affects about 13% of the world's population and represent a major public health concern due to the increasing prevalence and incidence. The aim of this study was to explore complementary strategies for GERD management based the natural compound palmitoylethanolamide (PEA), alone or associated with plant extracts with demonstrated anti-GERD activity (Zingiber officinale, Musa × paradisiaca, Opuntia ficus-indica and Olea europaea). For this purpose, two in vitro models based on the esophageal mucosa CP-B cell line were chosen. The first one was based on the exposure of esophageal cells to HCl, while the second one was based on lipopolysaccharide (LPS) treatment to cause a strong inflammatory cell response. Inflammation induced was assessed using a Luminex® assay, measuring the secretion of IL-1β, IL-6, IL-10, IL-8 and TNF-α. Results obtained demonstrate that PEA strongly decreased the inflammatory response elicited by HCl exposure. Moreover, the effect of PEA was enhanced by the presence of natural extracts of Zingiber officinale, Musa × paradisiaca, Opuntia ficus-indica and Olea europaea. PEA should be considered as an anti-GERD natural compound of interest.

The Impact of Chronic Cannabis Use on Esophageal Motility in Patients Referred for Esophageal Manometry

BACKGROUND

Tetrahydrocannabinol, the main psychoactive compound in cannabis, binds with high affinity to the cannabinoid 1 receptor. Small randomized controlled studies using conventional manometry have shown that the cannabinoid 1 receptor can modulate esophageal function, namely transient lower esophageal sphincter relaxation frequency and lower esophageal sphincter tone. The effect of cannabinoids on esophageal motility in patients referred for esophageal manometry has not been fully elucidated using high-resolution esophageal manometry (HREM). We aimed to characterize the clinical effect of chronic cannabis use on esophageal motility utilizing HREM.

METHODS

Patients who underwent HREM from 2009 to 2019 were identified at 4 academic medical centers. The study group consisted of patients with a noted history of chronic cannabis use, a diagnosis of cannabis-related disorder, or a positive urine toxicology screen. Age and gender-matched patients with no history of cannabis use were selected to form the control group. Data on HREM metrics based on the Chicago classification V3, and the prevalence of esophageal motility disorders were compared. Confounding effects of BMI and medications on esophageal motility were adjusted for.

RESULTS

Chronic cannabis use was found to be an independent negative predictor of weak swallows (β=-8.02, P =0.0109), but not a predictor of failed swallows ( P =0.6890). The prevalence of ineffective esophageal motility was significantly lower in chronic cannabis users compared with nonusers (OR=0.44, 95% CI 0.19-0.93, P =0.0384). There was no significant difference in the prevalence of other esophageal motility disorders between the 2 cohorts. In patients with dysphagia as their primary indication for HREM, chronic cannabis use was found to be independently associated with increased median integrated relaxation pressure (β=6.638, P =0.0153) and increased mean lower esophageal sphincter resting pressure (β=10.38, P =0.0084).

CONCLUSIONS

Chronic cannabis use is associated with decreased weak swallows and reduced prevalence of ineffective esophageal motility in patients referred for esophageal manometry. In patients referred for dysphagia, chronic cannabis use is associated with increased integrated relaxation pressure and lower esophageal sphincter resting pressure, though not to levels above the normal range.

Cannabis Use in Patients Presenting to a Gastroenterology Clinic: Associations with Symptoms, Endoscopy Findings, and Esophageal Manometry

Recreational cannabis use is increasing with its legalization in many states. Animal studies suggest cannabis can reduce transient lower esophageal sphincter relaxations (TLESRS), reflux and vomiting, while human studies report conflicting findings. There are currently no large studies investigating gastrointestinal symptoms in patients with chronic cannabis use. This was a retrospective case-control study including patients who presented to an outpatient Gastroenterology office, with documented cannabis use. Their main presenting complaint, demographics, frequency and duration of cannabis use, endoscopic and high-resolution esophageal manometry (HREM) with impedance findings were recorded. Cannabis users were more likely to complain of abdominal pain (25% vs. 8%, p < 0.0001), heartburn (15% vs. 9%, p < 0.0001), and nausea & vomiting (7% vs. 1%, p < 0.0001). They were also more likely to have findings of esophagitis (8% vs. 3%, p = 0.0002), non-erosive gastritis (30% vs. 15%, p = 0.0001) and erosive gastritis (14% vs. 3%, p < 0.0001) on upper endoscopy. Cannabis users were more likely to have impaired esophageal bolus clearance (43% vs. 17%, p = 0.04) and a hypertensive lower esophageal sphincter (LES) (29% vs. 7%, p = 0.04). This study is the largest to date evaluating GI complaints of patients with chronic recreational cannabis use. Our results suggest that cannabis use may potentiate or fail to alleviate a variety of GI symptoms which goes against current knowledge.

Cannabinoid pharmacology and therapy in gut disorders

Cannabis sp. and their products (marijuana, hashish…), in addition to their recreational, industrial and other uses, have a long history for their use as a remedy for symptoms related with gastrointestinal diseases. After many reports suggesting these beneficial effects, it was not surprising to discover that the gastrointestinal tract expresses endogenous cannabinoids, their receptors, and enzymes for their synthesis and degradation, comprising the so-called endocannabinoid system. This system participates in the control of tissue homeostasis and important intestinal functions like motor and sensory activity, nausea, emesis, the maintenance of the epithelial barrier integrity, and the correct cellular microenvironment. Thus, different cannabinoid-related pharmacological agents may be useful to treat the main digestive pathologies. To name a few examples, in irritable bowel syndrome they may normalize dysmotility and reduce pain, in inflammatory bowel disease they may decrease inflammation, and in colorectal cancer, apart from alleviating some symptoms, they may play a role in the regulation of the cell niche. This review summarizes the main recent findings on the role of cannabinoid receptors, their synthetic or natural ligands and their metabolizing enzymes in normal gastrointestinal function and in disorders including irritable bowel syndrome, inflammatory bowel disease, colon cancer and gastrointestinal chemotherapy-induced adverse effects (nausea/vomiting, constipation, diarrhea).

Review: The Role of Cannabinoids on Esophageal Function-What We Know Thus Far

The endocannabinoid system (ECS) primarily consists of cannabinoid receptors (CBRs), endogenous ligands, and enzymes for endocannabinoid biosynthesis and inactivation. Although the presence of CBRs, both CB1 and CB2, as well as a third receptor (G-protein receptor 55 [GPR55]), has been established in the gastrointestinal (GI) tract, few studies have focused on the role of cannabinoids on esophageal function. To date, studies have shown their effect on GI motility, inflammation and immunity, intestinal and gastric acid secretion, nociception and emesis pathways, and appetite control. Given the varying and sometimes limited efficacy of current medical therapies for diseases of the esophagus, further understanding and investigation into the interplay of the ECS on esophageal health and disease may present new therapeutic modalities that may help advance current treatment options. In this brief review, the current understanding of the ECS role in various esophageal functions and disorders is presented.

Dronabinol increases pain threshold in patients with functional chest pain: a pilot double-blind placebo-controlled trial

Noncardiac chest pain is associated with poor quality of life and high care expenditure. The majority of noncardiac chest pain is either gastresophageal reflux disease related or due to esophageal motility disorders, and the rest are considered functional chest pain (FCP) due to central and peripheral hypersensitivity. Current treatment of FCP improves 40-50% of patients. Cannabinoid receptors 1 (CB1) and 2 (CB2) modulate release of neurotransmitters; CB1 is located in the esophageal epithelium and reduces excitatory enteric transmission and potentially could reduce esophageal hypersensitivity. We performed a prospective study to evaluate its effects on pain threshold, frequency, and intensity in FCP. Subjects with FCP received dronabinol (5 mg, twice daily; n = 7; average age, 44 years; mean body mass index, 26.7) or placebo (n = 6; average age, 42 years; mean body mass index, 25.9) for 28 days (4 weeks). Chest pain, general health, and anxiety/depression questionnaires were assessed at baseline and at 4 weeks. Subjects underwent an esophageal balloon distention test prior to treatment and on last day of the study. Dronabinol increased pain thresholds significantly (3.0 vs. 1.0; P = 0.03) and reduced pain intensity and odynophagia compared to placebo (0.18 vs. 0.01 and 0.12 vs. 0.01, respectively, P = 0.04). Depression and anxiety scores did not differ between the groups at baseline or after treatment. No significant adverse effects were observed. In this novel study, dronabinol increased pain threshold and reduced frequency and intensity of pain in FCP. Further, large scale studies are needed to substantiate these findings.

Changes in Gene Expression Patterns of Circadian-Clock, Transient Receptor Potential Vanilloid-1 and Nerve Growth Factor in Inflamed Human Esophagus

Circadian rhythm is driven by the molecular circadian-clock system and regulates many physiological functions. Diurnal rhythms in the gastrointestinal tract are known to be related to feeding pattern, but whether these rhythms are also related to the gastrointestinal damage or injuries; for example, gastroesophageal reflux disease (GERD), is unclear. This study was conducted to determine whether expression of circadian-clock genes or factors involved in vagal stimulation or sensitization were altered in the esophagus of GERD patients. Diurnal patterns of PER1, PER2, BMAL1, CRY2, TRPV1, and NGF mRNA expression were found in patient controls, and these patterns were altered and significantly correlated to the GERD severity in GERD patients. Although levels of CRY1, TIM, CB1, NHE3, GDNF, and TAC1 mRNA expression did not show diurnal patterns, they were elevated and also correlated with GERD severity in GERD patients. Finally, strong correlations among PER1, TRPV1, NGF and CRY2 mRNA expression, and among PER2, TRPV1 and CRY2 expression were found. Expression levels of CRY1 mRNA highly correlated with levels of TIM, CB1, NHE3, GDNF and TAC1. This study suggests that the circadian rhythm in the esophagus may be important for the mediation of and/or the response to erosive damage in GERD patients.

Mechanisms of reflux perception in gastroesophageal reflux disease: a review

Patients with reflux symptoms often do not have excessive esophageal acid exposure, and patients with severe gastroesophageal reflux often do not have reflux symptoms. Understanding why different types of reflux induce symptoms in different patients is vital for addressing therapeutic gaps in the treatment of gastroesophageal reflux disease (GERD). Here we review studies providing insight into how gastroesophageal reflux is perceived, with a focus on comparing reflux characteristics and esophageal sensitivity among subgroups of patients with GERD. The available studies indicate that patients with nonerosive reflux disease have fewer acid reflux episodes and thus less esophageal acid exposure than patients with reflux esophagitis but perceive less intense stimuli because of greater esophageal sensitivity. Reflux characteristics other than acidity, such as the presence of bile, pepsin, liquid, or gas in reflux, and the proximal extent or volume of reflux, may also contribute to symptom perception. Factors contributing to greater esophageal sensitivity may include impaired mucosal barrier function, peripherally mediated esophageal sensitivity (enhanced esophageal receptor signaling), and centrally mediated esophageal sensitivity (physiological stressors, sensitization of spinal sensory neurons). Further insight into mechanisms of reflux perception may require a shift toward studies aimed at understanding predisposing cellular, molecular, and genetic factors.