Current but not past hepatitis B virus infection is associated with a decreased risk of nonalcoholic fatty liver disease in the Chinese population: A case-control study with propensity score analysis.

The relation between hepatitis B virus (HBV) infection and fatty liver has been addressed by several observational studies, but their results remain controversial. To date, no study has precisely investigated the association of current and past HBV infection with the risk of nonalcoholic fatty liver disease (NAFLD) in the Chinese population. Therefore, we conducted a hospital-based case-control study in southwestern China to clarify this issue. A total of 631 newly ultrasound-diagnosed NAFLD cases and 2357 controls were selected from 123 243 consecutive patients admitted to a tertiary-care hospital between January 2015 and December 2016. Multivariate logistic regression was employed to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). A propensity score was developed for adjustment and matching. Subgroup analysis was conducted to identify potential effect modifiers. Current and past HBV infection had an overall prevalence of 9.7% and 55.2%, respectively. In the fully adjusted model, current HBV infection was associated with a decreased risk of NAFLD (OR 0.64; 95% CI 0.42-0.95). A similar inverse association was observed in both propensity-score-adjusted (OR 0.58; 95% CI 0.40-0.86) and propensity-score-matched analyses (OR 0.61; 95% CI 0.40-0.92).The inverse association was stronger in patients with hypertension than in those without (Pinteraction  = .018).No significant association between past HBV infection and NAFLD risk was found. In conclusion, current but not past HBV infection is associated with a decreased risk of NAFLD in the Chinese population. The corresponding biological mechanisms remain to be elucidated.