Concurrent MASLD and Long-term Outcomes in HBV-infected Individuals: A Population-based Cohort Study.

OBJECTIVE: To examine the influence of metabolic dysfunction-associated steatotic liver disease (MASLD) on long-term outcomes of patients with chronic hepatitis B virus (HBV) infection. METHODS: A total of 3,269 participants with chronic HBV infection from the Kailuan Cohort (median follow-up: 13.7 years) were enrolled to estimate the hazard ratios ( HRs) and 95% confidence intervals ( CIs) for outcomes associated with MASLD. In addition, 120,913 individuals without HBV infection were included to assess the independent and interactive associations between steatotic liver disease (SLD), cardiometabolic risk factors (CMRFs), and HBV infection. RESULTS: In individuals with chronic HBV infection, MASLD was not linked to primary liver cancer but was associated with an increased risk of extrahepatic cancers ( HR= 1.50, 95% CI, 1.01-2.25) and cardiovascular diseases ( HR= 1.98, 95% CI, 1.49-2.63), especially in participants with normal alanine aminotransferase, mild SLD, and persistent MASLD. The risk of cardiovascular disease remained elevated in the participants with reversed MASLD. Joint analysis indicated a significant synergistic interaction between HBV infection, CMRFs, and primary liver cancer. CONCLUSIONS: In patients with chronic HBV infection, MASLD serves as a crucial indicator of significantly elevated systemic risk, underscoring the importance of addressing both virological control and metabolic health regardless of their current hepatic steatosis and liver enzyme status.