Why Outcomes Diverge in Chronic Hepatitis B with Steatotic Liver Disease: Lessons from Within-Study Contrasts

Background and Objectives: The “friend or foe” debate in chronic hepatitis B (CHB) with steatotic liver disease (SLD) partly arises from treating hepatic fat, metabolic burden, and steatohepatitis as one exposure and interpreting different outcomes together. Materials and Methods: This narrative review applies an exposure–stage–context framework to literature identified in PubMed and Web of Science through 21 September 2026. We synthesized outcome evidence from 119 reports, including 14 detailed examples, using within-study comparisons of exposures, outcomes, and patient subgroups. Results: Within individual cohorts, associations with the same outcome could diverge: steatosis or an SLD diagnosis was associated with lower hepatocellular carcinoma (HCC) or mortality risk, whereas greater metabolic burden was associated with higher risk. Favorable antigen-related associations also coexisted with adverse fibrosis trajectories. Steatohepatitis was associated with more severe fibrosis and liver-related events, while metabolic abnormalities and prolonged glycemic exposure were associated with adverse hepatic outcomes. Studies of metabolic dysfunction-associated steatotic liver disease (MASLD) reported greater cardiovascular risk, and a study of hepatitis B virus-positive patients with nonalcoholic fatty liver disease (NAFLD) reported more prevalent kidney disease. Baseline fibrosis, patient selection, and antiviral treatment shape these associations; lower relative risks can coexist with a high absolute event burden. Conclusions: Current hepatic fat, cumulative metabolic exposure, and established injury therefore carry different prognostic meanings. Their separate assessment helps explain part of the apparent paradox, while adverse steatosis findings and discrepancies in similar settings remain unresolved. The evidence is predominantly observational.