Hepatitis B virus infection and fatty liver in the general population

Abstract

In animal studies, expression of hepatitis B virus (HBV) proteins causes hepatic steatosis. We aimed to study the prevalence of fatty liver in people with and without HBV infection in the general population. We performed a cross-sectional population study in Hong Kong Chinese. Intrahepatic triglyceride content (IHTG) was measured by proton-magnetic resonance spectroscopy. One thousand and thirteen subjects (91 HBV patients and 922 controls) were recruited. The median IHTG was 1.3% (0.2-33.3) in HBV patients and 2.1% (0-44.2) in controls (p <0.001). Excluding subjects with significant alcohol consumption, the prevalence of nonalcoholic fatty liver disease was 13.5% (95% confidence interval [CI] 6.4%, 20.6%) in HBV patients and 28.3% (95% CI 25.3%, 31.2%) in controls (p=0.003). The fatty liver prevalence differed in HBV patients and controls aged 40-59 years but was similar in those aged 60 years or above. After adjusting for demographic and metabolic factors, HBV infection remained an independent factor associated with lower risk of fatty liver (adjusted odds ratio 0.42; 95% CI 0.20, 0.88; p=0.022). HBV patients also had a lower prevalence of metabolic syndrome (11.0% vs. 20.2%; p=0.034), but the difference was mainly attributed to lower triglyceride levels. Among HBV patients, viral genotypes, HBV DNA level and hepatitis B e antigen status were not associated with fatty liver. HBV infection is associated with a lower prevalence of fatty liver, hypertriglyceridemia and metabolic syndrome. Viral replication may affect lipid metabolism and this warrants further studies.