The Role of Homocysteine in Pediatric MASLD: A Bipotential Biomarker of Cardiovascular Risk and Liver Fibrosis

The increasing prevalence of metabolic dysfunction-associated fatty liver disease (MASLD) in children requires robust, non-invasive biomarkers to enable accurate disease staging and risk stratification. Elevated serum levels of homocysteine (Hcy) have emerged as potential risk factors for cardiometabolic disease in adults, including MASLD. In this observational retrospective study, we investigated the role of serum Hcy levels as a potential biomarker for disease severity and liver fibrosis in a pediatric cohort of 182 children with MASLD. In 89 patients, liver biopsy allowed the classification into metabolic dysfunction-associated steatohepatitis (MASH). Associations between Hcy, metabolic parameters, fibrosis scores, and histological features were examined, and the diagnostic performance of Hcy for liver fibrosis was evaluated using ROC analysis. Multivariate analyses identified elevated Hcy levels as independently associated with HOMA-IR (β = 0.55; <i>p</i> = 0.049), TG/HDL ratio (β = 3.23; <i>p</i> = 0.002), and liver fibrosis (β = 2.59; <i>p</i> = 0.04). Hcy showed a predictive accuracy of 81% for fibrosis. However, the combined diagnostic models of Hcy with non-invasive fibrotic scores (i.e., APRI and FIB-4) or TG/HDL ratio showed only a modest accuracy (AUC = 0.62-0.69). In conclusion, our data suggest that Hcy is associated with fibrosis and cardiometabolic risk. However, these results should be interpreted as exploratory and do not establish homocysteine as a diagnostic biomarker.