The role of sex hormones in abdominal aortic aneurysms: a topical review

Sex discrepancies have been reported for patients with abdominal aortic aneurysm (AAA) for decades. Men have a higher prevalence of disease, earlier onset, less morphological features obstructing eligibility for repair and better survival, both short and long term. In more recent years, several attempts have been made to identify the biologic or pathogenic factors contributing to these sex differences, including socioeconomic factors though all have failed. The greatest challenge is to reveal the variable mechanism for development of disease for both women and men, and secondly to identify the factors contributing to the progression of disease, and eventual rupture. Evaluations of diagnosed patients have failed to detect any factors associated with development of disease which would give a distinct explanation for the profound sex differences. Considering the obvious earlier trigger for development in men compared to women, excluding smoking, hypertension, hyperlipidemia as certified sole triggers, the remaining factors to explore are sex hormones or biological mechanisms. This topical review explores the contemporary publications on sex hormones and their association with AAA in women and men. The findings confirm the lack of scientific evidence for the influence of female and male sex hormones on development or progression of aneurysm disease. Weak indications support that women probably benefit from a longer reproductive history as a contributing protection against AAA development, influenced by smoking and heredity. There is some evidence that could support that, as for other manifestations of cardiovascular diseases, low testosterone levels in men, can contribute to an increased risk for AAA development. The influence of higher circulating levels of female sex hormones on risk development in men remains to be evaluated. In conclusion, this area will expand during the next decade, by combining registry-based and translational databases in stratified analysis for women and men, giving us more evidence that will contribute to important risk factor estimations for future cohorts at risk of AAA development.