Obesity and hiatal hernia may be non-allergic risk factors for esophageal eosinophilia in Japanese adults.

Esophageal eosinophilia (EE) is a basal condition of eosinophilic esophageal disorders including eosinophilic esophagitis (EoE) and asymptomatic EE. EoE is considered as an allergic disorder, while it is unclear whether other non-allergic conditions are involved in the pathophysiology of EE. The aim of this study is to investigate the non-allergic risk factors for EE.This cross-sectional study included subjects who underwent esophagogastroduodenoscopy on a medical health check-up. We compared clinical characteristics between subjects with EE (n = 27) and those without EE (n = 5937).

The detection rate of EE was 0.45% (27/5964 persons). Of 27 subjects with EE, 20 subjects were symptomatic and 7 were asymptomatic. On univariate analysis, subjects with EE significantly had higher body mass index (BMI) compared to those without EE; 23.4 (4.4) vs 22.3 (4.5) kg/m², median (interquartile range), p = 0.005. Endoscopic findings revealed that subjects with EE had significantly higher proportion of hiatal hernia (29.6% vs 14.7%; p = 0.049). Subjects with EE were significantly younger and had higher proportion of bronchial asthma; 45 (11.5) vs 51 (18) years, p = 0.013; 25.9% vs 5.2%, p < 0.001, respectively. Multivariate analysis showed that subjects with EE were positively associated with BMI [odds ratio (OR) 1.11; 95% confidence interval (CI) 1.03-1.20; p = 0.010) and hiatal hernia (OR 2.63; 95% CI 1.12-6.18; p = 0.026) compared to those without EE. On trend test, advanced BMI classification had significant trend for increased prevalence of EE (p = 0.002).

Obesity and hiatal hernia may be non-allergic risk factors for EE in Japanese adults.