Low skeletal muscle mass is highly prevalent among patients undergoing maintenance hemodialysis (MHD) and is closely linked to protein-energy wasting and adverse clinical outcomes. Aspartate aminotransferase (AST), a routinely measured enzyme involved in amino acid metabolism, is expressed in skeletal muscle and may reflect muscle metabolic status beyond hepatic injury. However, the association between long-term AST exposure and low skeletal muscle mass in the dialysis population remains unclear.