Time-updated FIB-4 index predicts coronary artery calcification progression in individuals with metabolic dysfunction-associated steatotic liver disease.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disorder worldwide and is increasingly recognized as a multisystem disease that elevates cardiovascular disease (CVD) risk. Liver fibrosis, rather than steatosis itself, is considered the primary determinant of prognosis in MASLD. The Fibrosis-4 (FIB-4) index, a simple noninvasive fibrosis score, has been linked to adverse hepatic outcomes, but its value for predicting subclinical atherosclerosis remains unclear. We investigated whether time-updated FIB-4 predicts coronary artery calcification (CAC) progression in a large cohort of asymptomatic Korean adults. A total of 60,445 participants who underwent repeated coronary computed tomography and liver ultrasonography during health examinations between 2012 and 2023 were included. CAC progression, defined as incident CAC (Agatston score ≥ 1) or a significant increase in existing CAC, was assessed using time-dependent Cox regression models. Elevated FIB-4 was significantly associated with higher risk of CAC progression among participants with MASLD, independent of established CVD risk factors. In stratified analyses, the association was stronger in men and in individuals older than 40 years. These findings indicate that the time-updated FIB-4 index shows a modest association with subclinical atherosclerosis progression, primarily among men aged ≥ 40 years with MASLD, and may serve as an accessible marker reflecting subclinical cardiovascular risk rather than a validated predictor of risk stratification improvement.