Helicobacter pylori infection is not associated with nonalcoholic fatty liver disease

AIM: To determine whether Helicobacter pylori (H. pylori) infection confers a higher risk of Nonalcoholic fatty liver disease (NAFLD). METHODS: Healthy people who underwent health screening were analyzed retrospectively. Inclusion criteria were age >= 20 years, history of H. pylori infection, and recorded insulin level. Participants were classified as H. pylori positive or negative according to C-13 urea breath tests. NAFLD was defined using the hepatic steatosis index (HSI) and NAFLD liver fat score (NAFLD-LFS). Those with an HSI > 36 or NAFLD-LFS > -0.640 were considered to have NAFLD. Multivariable logistic regression was performed to identify risk factors for NAFLD. RESULTS: Three thousand six hundred and sixty-three people were analyzed and 1636 (44.7%) were H. pylori positive. H. pylori infection was associated with older age, male gender, hypertension, higher body mass index, and a dyslipidemic profile. HSI differed significantly between H. pylori positive and negative subjects (median 33.2, interquartile range (IQR) 30.0-36.2 for H. pylori-positive vs median 32.6, IQR 29.8-36.0 for negative participants, P = 0.005), but NAFLD-LSF did not [median -1.7, IQR -2.4 - -0.7 vs median -1.8, IQR -2.4-(-0.7), respectively, P = 0.122]. The percentage of people with NAFLD did not differ between infected and uninfected groups: HIS, 26.9% vs 27.1%, P = 0.173; NAFLD-LFS, 23.5% vs 23.1%, P = 0.778. H. pylori infection was not a risk factor, but C-reactive protein concentration and smoking were significant risk factors for NAFLD. CONCLUSION: H. pylori infection is not a risk factor for NAFLD as indicated by HSI or NAFLD-LFS. Prospective, large-scale studies involving liver biopsies should be considered.