Lean/normal-weight metabolic dysfunction-associated fatty liver disease is a risk factor for reflux esophagitis.

Aim: Reflux esophagitis is associated with metabolic dysfunction. Recently, fatty liver has been redefined as metabolic dysfunction-associated fatty liver disease (MAFLD). We investigated the impact of MAFLD and its subtypes on the incidence of reflux esophagitis.

Methods: This multicenter, observational cohort study enrolled 9100 consecutive health-check examinees who underwent esophagogastroduodenoscopy and ultrasonography. All patients were classified into the MAFLD or non-MAFLD group. Based on the Asian cut-off value for body mass index (BMI), the MAFLD group was further classified into the lean/normal-weight (BMI <23 kg/m ) and overweight/obese (BMI ≥23 kg/m ) subgroups. The impact of MAFLD and its subtypes on the cumulative incidence of reflux esophagitis was evaluated using multivariable Cox proportional hazards regression analysis.

Results: MAFLD was diagnosed in 26.5% (2416/9100) of patients. Multivariable Cox proportional hazards regression analysis indicated that MAFLD (hazard ratio [HR] 1.2183; 95% confidence interval [CI] 1.0954-1.3550; p = 0.0003), hiatal hernia, and aging were independent risk factors for reflux esophagitis. Stratification analysis indicated that cumulative incidence of reflux esophagitis among patients with MAFLD was significantly higher in the lean/normal-weight than in the overweight/obese group (HR 1.3274; 95% CI 1.0043-1.7547; p = 0.0466). Among various metabolic factors, visceral adiposity was the only independent metabolic risk factor for reflux esophagitis (HR 2.8331; 95% CI 1.0201-7.8691; p = 0.0457) in the lean/normal-weight MAFLD group.

Conclusions: MAFLD, in particular lean/normal-weight MAFLD, is independent risk factor for reflux esophagitis. Furthermore, visceral adiposity was identified as the most strong metabolic risk factor for reflux esophagitis in lean/normal-weight patients with MAFLD.