MMP9 and diabetes mellitus: Pioglitazone (PPARγ agonist) attenuates MMP-9 expression and activity across vascular and metabolic settings: in human saphenous-vein tissue from patients with diabetes, pioglitazone reduced MMP-dependent remodeling and improved ex vivo vascular reactivity; experimental and clinical studies in metabolic disease similarly report lower serum or tissue MMP-9, consistent with PPARγ-mediated dampening of NF-κB/AP-1 and macrophage MMP-9 release [91,92].