Abstract
Lymphedema, traditionally viewed as a mechanical consequence of lymphatic obstruction, is increasingly recognized as a complex disorder rooted in metabolic dysfunction, particularly insulin resistance and chronic hyperinsulinemia. This paradigm-shifting hypothesis redefines lymphedema as a vascular complication driven by systemic metabolic stress, where prolonged hyperinsulinemia impairs lymphatic endothelial cell (LEC) function, triggering inflammation, oxidative stress, and structural damage. Insulin resistance disrupts the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway, critical for lymphangiogenesis and endothelial integrity, leading to compromised lymphatic drainage. Pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), exacerbate this dysfunction by activating nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and promoting reactive oxygen species (ROS) production, while advanced glycation end products (AGEs) engaging RAGE amplify fibrosis and endothelial apoptosis. Glucagon-like peptide-1 receptor agonists (GLP-1RAs), such as liraglutide and semaglutide, offer a revolutionary therapeutic approach by addressing both metabolic and vascular components of lymphedema. By enhancing PI3K/AKT signaling, GLP-1RAs restore insulin sensitivity, mitigate hyperinsulinemia, and suppress inflammatory pathways (NF-κB, TLR4). Their activation of VEGF-C/VEGFR-3 and endothelial nitric oxide synthase (eNOS)/NO pathways promotes lymphangiogenesis and reduces ROS-induced damage, enhancing lymphatic vessel repair. Clinical evidence, including a 2024 case report, demonstrates significant reductions in limb volume (from 10.3% to 3.4%) and restored lymphatic function in breast cancer-related lymphedema following GLP-1RA therapy. Localized administration optimizes therapeutic outcomes by targeting LECs, minimizing systemic side effects. This narrative review synthesizes lymphedema's metabolic pathophysiology, proposes localized semaglutide as a novel therapy, and suggests experimental protocols to advance lymphedema management.