ANPEP and obesity due to melanocortin 4 receptor deficiency: Adiponectin (APN), a peptide secreted by adipose tissue, enhances insulin sensitivity and regulates lipid metabolism.4,5 Reduced APN activity is linked to metabolic syndrome, including obesity, type 2 diabetes, and cardiovascular diseases.6,7 Beyond its metabolic roles, APN also has anti-inflammatory effects.8,9 Studies have shown a negative correlation between APN, pro-inflammatory cytokines, illness severity, and mortality in septic patients.10,11 Our previous research similarly found that low APN levels were associated with 28-day mortality in sepsis patients.12