Amino Acids—Potential Biomarkers of Histological Features for MASLD in Pediatric Obesity

Metabolically-dysfunction-associated steatotic liver disease (MASLD) represents the most common chronic liver disease in the pediatric population, and its prevalence has doubled over the past decade. The etiology is multifactorial, including genomic risk factors, perinatal and developmental or behavioral factors. Still, many cases of MASLD are associated with being overweight and obesity, particularly in children who have poor dietary habits and sedentary lifestyles that contribute to excessive weight gain. Given the progressive and heterogeneous nature of MASLD, early identification of high-risk patients before the development of severe liver disease is a major clinical priority. Recent studies indicate that disorders of amino acid metabolism are closely linked to both obesity and MASLD, reflecting profound alterations in systemic metabolic homeostasis. The reported data sustain significant changes in circulating amino acid profiles, particularly elevated levels of branched-chain amino acids (BCAAs) and aromatic amino acids. These alterations are thought to reflect fundamental metabolic disturbances, including insulin resistance, compromised mitochondrial activity, and altered hepatic lipid metabolism. Consequently, alterations in amino acid metabolism have been proposed as potential biomarkers for disease progression and metabolic dysfunction in MASLD. This review aims to evaluate the correlation between the amino acid profile and histological changes in pediatric MASLD, including steatosis, steatohepatitis, and fibrosis.