Weight Gain Is Associated with Short-Term FIB-4 Increase and Concurrent Metabolic Change in People with HIV and Metabolic Dysfunction-Associated Steatotic Liver Disease

Background: Short-term variation in the Fibrosis-4 index (FIB-4) may identify people who warrant further liver assessment. We evaluated longitudinal FIB-4 changes and associated metabolic factors in people with HIV (PWH) and metabolic dysfunction-associated steatotic liver disease (MASLD). Methods: This retrospective cohort included 683 PWH with ultrasound-defined MASLD who underwent routine clinical and laboratory assessments approximately every three months. A prespecified FIB-4 increase required both a ≥20% rise and crossing to ≥1.3 among participants with baseline FIB-4 < 1.3, or a ≥20% rise among those with baseline FIB-4 ≥ 1.3. Results: Of 683 enrolled participants, 655 were analyzed longitudinally. Over a median follow-up of 12.0 months, 59 (9.0%) met the FIB-4 increase definition, corresponding to 8.8 events per 100 person-years. Weight gain was associated with this outcome (adjusted hazard ratio 1.19 per 1% increase, 95% CI 1.14–1.24), whereas HIV- and antiretroviral therapy-related variables were not. Transition from non-obesity to obesity was associated with the outcome (odds ratio 8.45, 95% CI 3.57–20.02). Weight change also correlated with concurrent changes in total cholesterol, triglycerides, fasting glucose, and liver enzymes (all p < 0.01). Conclusions: Weight gain was associated with short-term FIB-4 increase and with concurrent metabolic change in PWH with MASLD.