Immunoglobulin G-mediated food intolerance and metabolic syndrome influence the occurrence of reflux esophagitis in Helicobacter pylori-infected patients

BACKGROUND Reflux esophagitis has an increasing prevalence and complex and diverse symptoms. Identifying its risk factors is crucial to understanding the etiology, prevention, and management of the disease. The occurrence of reflux esophagitis may be associated with food reactions, Helicobacter pylori (H. pylori) infection, and metabolic syndromes. AIM To investigate the risk factors for reflux esophagitis and analyze the effects of immunoglobulin (Ig) G-mediated food intolerance, H. pylori infection, and metabolic syndrome on reflux esophagitis. METHODS Outpatients attending the Second Medical Center of the PLA General Hospital between 2017 and 2021 were retrospectively enrolled. The patients' basic information, test results, gastroscopy results, H. pylori test results, and IgG-mediated food intolerance results were collected. Multivariate logistic regression analysis was used to analyze risk factors for reflux esophagitis. Statistical mediation analysis was used to evaluate the effects of IgG-mediated food intolerance and metabolic syndrome on H. pylori infection affecting reflux esophagitis. RESULTS A total of 7954 outpatients were included; the prevalence of reflux esophagitis, IgG-mediated food intolerance, H. pylori infection, and metabolic syndrome were 20.84%, 61.77%, 35.91%, and 60.15%, respectively. Multivariate analysis showed that the independent risk factors for reflux esophagitis included IgG-mediated food intolerance (OR = 1.688, 95%CI: 1.497-1.903, P < 0.00001) and metabolic syndrome (OR = 1.165, 95%CI: 1.030-1.317, P = 0.01484), and the independent protective factor for reflux esophagitis was H. pylori infection (OR = 0.400, 95%CI: 0.351-0.456, P < 0.00001). IgG-mediated food intolerance had a partially positive mediating effect on H. pylori infection as it was associated with reduced occurrence of reflux esophagitis (P = 0.0200). Metabolic syndrome had a partially negative mediating effect on H. pylori infection and reduced the occurrence of reflux esophagitis (P = 0.0220). CONCLUSION Patients with IgG-mediated food intolerance and metabolic syndrome were at higher risk of developing reflux esophagitis, while patients with H. pylori infection were at lower risk. IgG-mediated food intolerance reduced the risk of reflux esophagitis pathogenesis in patients with H. pylori infection; however, metabolic syndrome increased the risk of patients with H. pylori infection developing reflux esophagitis.