Some of the effective factors in the pathogenesis of gastro-oesophageal reflux disease

Causal relationship between air pollution, lung function, gastroesophageal reflux disease, and non-alcoholic fatty liver disease: univariate and multivariate Mendelian randomization study

Background

The association between air pollution, lung function, gastroesophageal reflux disease, and Non-alcoholic fatty liver disease (NAFLD) remains inconclusive. Previous studies were not convincing due to confounding factors and reverse causality. We aim to investigate the causal relationship between air pollution, lung function, gastroesophageal reflux disease, and NAFLD using Mendelian randomization analysis.

Methods

In this study, univariate Mendelian randomization analysis was conducted first. Subsequently, Steiger testing was performed to exclude the possibility of reverse association. Finally, significant risk factors identified from the univariate Mendelian analysis, as well as important factors affecting NAFLD from previous observational studies (type 2 diabetes and body mass index), were included in the multivariable Mendelian randomization analysis.

Results

The results of the univariable Mendelian randomization analysis showed a positive correlation between particulate matter 2.5, gastroesophageal reflux disease, and NAFLD. There was a negative correlation between forced expiratory volume in 1 s, forced vital capacity, and NAFLD. The multivariable Mendelian randomization analysis indicated a direct causal relationship between gastroesophageal reflux disease (OR = 1.537, p = 0.011), type 2 diabetes (OR = 1.261, p < 0.001), and NAFLD.

Conclusion

This Mendelian randomization study confirmed the causal relationships between air pollution, lung function, gastroesophageal reflux, and NAFLD. Furthermore, gastroesophageal reflux and type 2 diabetes were identified as independent risk factors for NAFLD, having a direct causal connection with the occurrence of NAFLD.

Esophageal Mucosal Resistance in Reflux Esophagitis: What We Have Learned So Far and What Remains to Be Learned

Gastroesophageal reflux disease (GERD) has the highest prevalence among diseases of the digestive system and is characterized by a significant decrease in patients' quality of life, comparable to arterial hypertension and coronary heart disease. One in every ten cases of reflux esophagitis leads to the formation of Barrett's esophagus, which is associated with a high risk of esophagus adenocarcinoma. The key factors determining the progression of the disease are the frequency and duration of the reflux of the stomach's contents. As a result, refluxate, which includes hydrochloric acid, pepsin, and, in the case of concomitant duodeno-gastric reflux, bile acids and lysolecithin, is thrown into the overlying sections of the digestive tract. At the same time, in addition to aggression factors, it is necessary to take into account the state of resistance in the esophageal mucosa to the effects of aggressive refluxate molecules. This review was prepared using systematized data on the protective properties of the esophageal mucosa and modern methods to assess the mucosal barrier in reflux esophagitis. Lesions of the epithelial barrier structure in the esophagus are recognized as the main pathogenetic factor in the development of reflux esophagitis and are a potentially significant therapeutic target in the treatment of GERD and Barrett's esophagus. This article presents the characteristics of the esophageal mucosal barrier and the protective mechanisms of the esophagus's mucous membrane in conditions of gastroesophageal reflux. Diagnostic approaches for assessing the course of reflux esophagitis are described for both histological criteria and the possibility of a comprehensive assessment of the state of mucins, tight-junction proteins, and the proliferative activity of the mucosa, including under the conditions of ongoing therapy.

A Study on Risk Factors Associated with Reflux Esophagitis in Patients Undergoing Esophageal Cancer Surgery

Objective

To investigate the risk factors associated with reflux esophagitis in patients undergoing esophageal cancer surgery and to provide reference for the prevention and treatment of reflux esophagitis.

Methods

In the manner retrospective study, the data of 300 patients with esophageal cancer who received the surgical treatment in our hospital (January 2018-December 2020) were retrospectively reviewed. The 300 patients were divided into the occurrence group (n = 45) and nonoccurrence group (n = 255) depending on whether they had reflux esophagitis after surgery. The social demographic data and clinical data of the patients in the two groups were collected. These data were classified into the personal factors and surgical factors. The single-factor analysis method was adopted to analyze the effects of the personal and surgical factors on reflux esophagitis. The factors with statistically significant differences in the single-factor analysis were analyzed by logistic regression to verify the factors were the risk factors associated with reflux esophagitis in patients undergoing esophageal cancer surgery.

Results

The differences in the bodyweight, body mass index (BMI), length of the resected esophagus, surgical approach, intraoperative blood loss, gastrointestinal decompression volume, and surgery time between the two groups were of statistical significance (P < 0.05). After being tested by the logistics multivariate analysis, length of the resected esophagus, whole stomach reconstruction, intraoperative blood loss, and surgery time were identified as the risk factors associated with reflux esophagitis in patients undergoing esophageal cancer surgery.

Conclusion

The length of the resected esophagus, whole stomach reconstruction, intraoperative blood loss, and surgery time were the risk factors associated with reflux esophagitis in patients undergoing esophageal cancer surgery. It is necessary to choose the appropriate surgical approach according to the patients' conditions in practice and to strengthen the prevention and treatment of reflux esophagitis.

Nitric oxide and inducible nitric oxide synthase levels in EE and NERD patients

Aim

This article aimed to evaluate nitric oxide (NO) and nitric oxide synthase (iNOS) markers in patients with erosive esophagitis (EE) and those with non-erosive reflux disease (NERD) and compare them with the control group.

Background

Gastro-esophageal reflux disease (GERD) is one of the most common disturbances of the upper digestive tract. Inducible nitric oxide synthase (iNOS) is expressed in esophageal adenocarcinoma. NO, the product of this enzyme, has been implicated in the pathogenesis of this condition. Nevertheless, the data on whether iNOS and NO are expressed in the early stages of GERD is conflicting.

Methods

In this study, tissue samples were obtained from fifty-four patients (27 with erosive esophagitis and 27 with non-erosive reflux disease) and 27 controls. Tissue concentrations of nitrite, nitrate, and iNOS were measured using Enzyme-Linked Immune-sorbent Assay (ELISA). The Bradford method was used to determine the protein concentration of samples. The results were analyzed by SPSS software (version 22.0). In multiple comparisons, the Tukey test was performed, and p < 0.05 was considered as the level of significance.

Results

Tissue amounts of iNOS were significantly higher (p= 0.001) in EE patients compared with the control group. There was a significant difference (p= 0.01) in this factor between EE patients and patients with NERD. Moreover, tissue levels of nitrite and nitrate were significantly higher (p = 0.001) in patient groups compared with the control group.

Conclusion

It was observed that NO and iNOS protein were increased in human esophagitis tissue. The results indicated that nitric oxide and iNOS levels are useful and effective markers in the pathogenesis of GERD. While the results are not certain, it is thought that a link exists between the expressions of iNOS and disease progression.

The Relationship between Serum Total Oxidant Status, Total Antioxidant Status, and Oxidative Stress Index with Severity Levels of Gastroesophageal Reflux Disease: A Literature Review

Gastroesophageal reflux disease (GERD) is a global health problem in which the prevalence is increasing over periods. This disease is a significant cause of disorders in the upper gastrointestinal tract with very complex pathogenesis. Oxidative stress (OS) due to gastric acid reflux plays a role in the inflammatory response of the esophageal epithelium. Several OS markers have been widely studied and are thought to affect the severity degree of the esophageal mucosa. However, there has been no research on total oxidant status (TOS), total antioxidant status (TAS), and OS index (OSI) in the adult with GERD; hence the aim of this review was to determine the association between TOS, serum TAS, and OSI with the GERD degree. A literature review was conducted by searching articles related to the TOS, TAS, OSI, and its correlation with GERD degree on an online database, particularly Pubmed and Google scholar. We conclude that TAS and OSI might influence the severity of GERD; however, further clinical study is needed to prove this theory.

Prevalence and risk factors for gastroesophageal reflux disease in the Indian population: A meta-analysis and meta-regression study

BACKGROUND

Indian population-based studies on the prevalence and risk factors for gastroesophageal reflux disease (GERD) are scanty, and a meta-analysis and a meta-regression of prevalence and risk factors based on the existing data have not yet been reported.

METHODS

A systematic review of all the available publications from India reporting data regarding prevalence and risk factors of GERD was performed. Heterogeneity was assessed using I² statistics. The meta-analysis was undertaken to measure the average proportion reported in the existing studies, and meta-regression models were used to explore the risk factors for it.

RESULTS

The nine studies included 20,614 subjects; the prevalence of GERD ranged from 5% to 28.5%. The summary effect size (weighted average proportion) estimated by meta-analytic model was 0.1415 (95% confidence interval [CI] 0.099 to 0.197). The results for the test of heterogeneity that included tau² (0.37, 95% CI 0.21 to 1.80), I² (98.9%, 95% CI 98.01 to 99.77), and the Q-statistic (707.670; p < 0.0001) suggested high heterogeneity in the effect sizes. The pooled proportion of GERD (random-effects model) was 15.573 (95% CI 11.046 to 20.714). In the meta-regression model, sample size (p = 0.005) explained about 50% of the heterogeneity.

CONCLUSION

The pooled prevalence of GERD in the Indian population is 15.6 (95% CI 11.046 to 20.714). The risk factors were age, body mass index (BMI), non-vegetarian diet, tea/coffee intake, tobacco, and alcohol consumption. However, there was significant heterogeneity in the studies.

Some of the effective factors in the pathogenesis of gastro-oesophageal reflux disease

Oesophageal adenocarcinoma is one of the most fatal tumours to affect the digestive tract and is the eighth most common malignancy worldwide. Gastro‐oesophageal reflux has an important role in the incidence of adenocarcinoma of the oesophagus. Gastro‐oesophageal reflux disease (GERD) is a multifactorial, acid‐peptic disorder that results from the reflux of noxious material from the stomach into the oesophagus. The refluxed material causes the occurrence of oesophageal inflammation which creates a condition that is called reflux oesophagitis. The prevalence of this disease has increased dramatically in recent decades, mostly in the western world, where it affects about 10% to 30% of the population. The aetiology of oesophageal mucosal damage is complicated. Many inflammatory mediators are produced within the gastrointestinal (GI) tract, but their contributions in pathophysiology and disease pathogenesis have not been well investigated. Despite the protective barrier provided by the oesophageal mucosa, refluxed materials can cause oxidative injury and in?ammatory responses that involve the epithelium and immune cells. The analysing cellular events in gastro‐ oesophageal reflux disease and physiological responses to such conditions are important and necessary for a better grasp of the pathogenesis of GERD and the expansion of new treatments. Therefore, we want to discuss some of the important and key factors of GERD disease in this article.