Abdominal aortic aneurysm: Sex differences

Objective: Abdominal aortic aneurysm (AAA) predominantly affects an elderly male population. Even so, AAA appears more detrimental in women, who experience a higher risk of aneurysm rupture and a worse outcome after surgery than men. Why women are privileged from yet are worse off once affected has been attributed to an effect of sex hormones. This review summarizes the knowledge of sex differences in AAA and addresses the changes in the aneurysm wall from a gender perspective. Method: Standard reporting guidelines set by the PRISMA Group were followed to identify studies examining AAA from a gender perspective. Relevant reports were identified using two electronic databases: PubMed and Web of Science. The systematic search was performed in two stages: firstly, using the terms AAA and gender/sex/women; and secondly, adding the terms "elastin", "collagen" and "vascular smooth muscle cells", in order to filter the search for studies relevant to our focus on the aneurysm wall. Conclusion: Current studies support the theory that sex has an effect on aneurysm formation, yet are inconclusive about whether or not aneurysm formation is dependent on female/male sex hormones or a lack thereof. The studies in women are scarce and out of those most reports primarily address other end-points, which limit their ability to illuminate an effect of sex on aneurysm formation. The complexity of the human menstrual cycle and menopausal transition are difficult to mimic in animal models, which limit their applicability to AAA formation in humans.