While hyperglycemia significantly increases PAI-1 expression [36] in cerebral arteries and also downregulates t-PA expression and activity [37], which may increase inflammatory cell accumulation in the lesioned vessels and increase arterial intima-media thickness, and thus attenuates aneurysm diameter [38], and thereby decreases saccular aneurysm (Stage 3 IA formation). This evidence concerns the gene SERPINE1 and aneurysm.