"Eosinophilic esophagitis," a designated intractable disease, is increasing in Japan — Involvement of smoking and alcohol consumption confirmed by Osaka Metropolitan University

A research group led by Clinical Lecturer Akinari Sawada, Associate Professor Fumio Tanaka, and Professor Yasuhiro Fujiwara of Osaka Metropolitan University Graduate School of Medicine and Graduate Student Yasutaka Ihara of the Department of Medical Statistics at Osaka Metropolitan University and Lecturer Takumi Imai (currently Specially Appointed Associate Professor of Kobe University Hospital) has announced their research results showing that the incidence of eosinophilic esophagitis (EoE) in Japan has rapidly increased in recent years. Large-scale insurance claim data on about 15.2 million people collected from 2005 to 2022 were analyzed. The incidence in 2022 was 2.82 per 100,000 person-years, a threefold increase from 2017. The findings are expected to contribute to the elucidation of the pathophysiology and the development of preventive methods. The results were published in the international journal Clinical Gastroenterology and Hepatology on May 14.

EoE, a designated incurable disease, is a chronic allergic disease that causes heartburn and other esophageal symptoms and is caused by an increase in eosinophils, a type of white blood cells, in the mucosal epithelium of the esophagus due to food and airborne allergens. It has been reported that this disease is more common in men in their 30s and 40s and has been increasing dramatically in Europe and the United States over the past 30 years. Meanwhile, trends were unknown in Asia, including Japan, where no surveys had been conducted.

In this study, the research group analyzed the database provided by JMDC, which consists of claims issued to health insurance societies and health checkup data. In the database, information on health insurance society members, including diagnoses made during insurance treatment, can be traced. An analysis of large-scale insurance claim data on 15,200,895 patients showed that the number of EoE patients increased dramatically over the past 20 years. The incidence and prevalence in 2022 were 2.82 per 100,000 person-years and 10.68 per 100,000 people, respectively. Analysis of EoE-associated factors also revealed that smoking contributes to a decreased risk of developing EoE, while alcohol consumption contributes to an increased risk of developing EoE. Although the disease is said to be more common in developed countries, the incidence in Japan was found to be lower than the rates reported for Caucasians and Asian Americans in the United States, indicating that genetic and environmental factors contribute to the development of EoE.

Sawada said, "Eosinophilic esophagitis, a designated incurable disease, is relatively new and has been exploding in Europe and the United States since the 1990s. We could also confirm the rapid increase in Japan using insurance claim data. Eosinophilic esophagitis must be considered in the differential diagnosis of patients with common esophageal symptoms such as trouble swallowing and heartburn, but awareness of the disease is still insufficient. We hope this study will help to increase awareness."

Journal Information
Publication: Clinical Gastroenterology and Hepatology
Title: Epidemiology and Risk Factors of Eosinophilic Esophagitis in Japan: A Population-Based Study
DOI: 10.1016/j.cgh.2024.04.035