Abdominal aortic aneurysms (AAAs) primarily affect elderly men. The effect of sex on aneurysm development has been associated with the effects of sex hormones through mechanisms that are not fully understood. The present study examined the association between the levels of sex hormones and the occurrence of AAAs in elderly men.

A prospective case-control study was conducted of 452 men aged 65 years participating in screening for AAAs from 2013 to 2019. Of the 452 men, 230 had an AAA and 222 an aortic diameter of <30 mm (control group). Questionnaires and blood samples were collected and stored consecutively. The serum levels of total testosterone, estradiol, progesterone, luteinizing hormone, and sex hormone-binding globulin were analyzed using electrochemiluminescent immunoassays. Multivariable logistic regression analysis was used to assess the association between sex hormones and AAA.

The median aneurysm diameter was 33 mm. Men with AAA had greater estradiol (93 pmol/L vs 84 pmol/L; P =.003) and progesterone (0.41 nmol/L vs 0.17 nmol/L; P < .001) levels compared with the controls. The testosterone levels were lower in the AAA group than in the control group (13 nmol/L vs 14 nmol/L; P = .026). AAA was associated with detectable levels of progesterone (odds ratio [OR], 6.69; 95% confidence interval [CI], 3.86-11.47), smoking (OR, 5.26; 95% CI, 3.12-8.85), coronary heart disease (OR, 4.06; 95% CI, 1.92-8.58), and a body mass index >25 kg/m² (OR, 2.26; 95% CI, 1.34-3.82).

The observed higher estradiol and progesterone levels in men with an AAA suggest an effect of sex hormones on aneurysm development. The association between progesterone levels and the aortic diameter stresses the importance of focusing on the potential effect of this unconsidered female sex hormone on aneurysm formation.