AGT and achalasia-alacrima syndrome: Preclinical studies show that metformin and other glucose-lowering agents (e.g., DPP-4 inhibition with sitagliptin; PPAR-γ agonism with pioglitazone) can attenuate Ang II- or elastase-induced AAAs by reducing macrophage chemokines, MMP expression/activity, and oxidative stress in the aortic wall [139,140,141,142,143,144,145,146].