Sex differences in abdominal aortic aneurysms

Abstract

Abdominal aortic aneurysm (AAA) is a vascular disorder with a high case fatality rate in the instance of rupture. AAA is a multifactorial disease, and the etiology is still not fully understood. AAA is more likely to occur in men, but women have a greater risk of rupture and worse prognosis. Women are reportedly protected against AAA possibly by premenopausal levels of estrogen and are, on average, diagnosed at older ages than men. Here, we review the present body of research on AAA pathophysiology in humans, animal models, and cultured cells, with an emphasis on sex differences and sex steroid hormone signaling.

Keywords: abdominal aortic aneurysm; androgen signaling; estrogen signaling; sex differences; sex steroid hormones.

Fig. 1.

Diagram of sex steroid hormones on abdominal aortic aneurysm (AAA) development. Estrogen signaling blunts AAA development by dampening inflammation, oxidative stress, and proteolysis. Androgen signaling may facilitate AAA development by promoting inflammation, oxidative stress, and proteolysis.

Fig. 2.

Mortality rates for abdominal aortic aneurysms (AAA) in the United States for the years of 2015 and 2016 stratified by age and sex. Mortality rates for AAA are higher for men in all age groups. Data correspond to the following ICD-10 Codes: I71.3 (AAA, ruptured), I71.4 (AAA, without mention of rupture), I71.5 [thoracoabdominal aortic aneurysm (TAAA), ruptured], I71.6 (TAAA, without mention of rupture). These data are from Centers for Disease Control and Prevention, National Center for Health Statistics, Compressed Mortality File 1999–2016 on the CDC WONDER Online Database, released December 2017. Data are from the Compressed Mortality File 1999–2016, Series 20, No. 2V, 2017, as compiled from data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program. Accessed at https://wonder.cdc.gov/cmf-icd10.html.