ERα-dependent BCAA-nitrogen flux in sex-biased MASLD.

Sex-biased metabolic dysfunction-associated steatotic liver disease susceptibility is usually attributed to differences in adiposity, insulin resistance, and sex-hormone levels. I propose that hepatic estrogen receptor α shapes the partitioning of muscle-derived branched-chain amino acid carbon and amino nitrogen between oxidation, lipid synthesis, recycling, and disposal. This framework supports endocrine-state-aware biomarkers and sex-stratified trials integrating liver and muscle endpoints.