Department of Vascular Surgery, St. Olavs Hospital, Trondheim, Norway; Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: email@example.com.
The delayed development of abdominal aortic aneurysm (AAA) in women compared with men might be secondary to a protective effect from endogenous estrogens. The role of postmenopausal hormone therapy remains unclear. The aim of the present study was to evaluate the effect of female sex hormones compared with other risk factors associated with AAA through a long-term study of a large female cohort.
The present prospective cohort study included 20,024 postmenopausal women from the Norwegian Nord-Trøndelag Health Study. A total of 201 cases of AAA were identified during a median follow-up period of 18 years (295,554 person-years; 1995-2014). The data were recorded from questionnaires, physical measurements, medical records, blood sample test results, and the Norwegian Cause of Death Registry. The effect of risk factors was evaluated in a multiple Cox regression analysis. Multiple imputation was performed for missing data (n = 50 data sets). The serum estradiol concentrations in women with and without incidental AAAs were compared. The median interval from blood sample collection to the AAA diagnosis was 7 years.
Current smokers had >10-fold increased risk of incident AAA during the follow-up period (hazard ratio [HR], 10.9; 95% confidence interval [CI], 7.4-16.1). Positive associations were found for hypertension (HR, 2.0; 95% CI, 1.4-3.0) and coronary heart disease (HR, 2.2; 95% CI, 1.6-3.2). The HR associated with the current use of postmenopausal hormone therapy was 0.58 (95% CI, 0.6-1.5). No substantial difference in estradiol concentrations was found between women with and without AAA (P = .075).
The effect of female sex hormones on the risk of incident AAAs in women, as evaluated by the serum concentrations of estradiol and the use of postmenopausal hormone therapy, is clinically less important than the strong associations found with smoking, hypertension, and coronary heart disease.
Prospective studies evaluating risk factors for abdominal aortic aneurysm are few. We studied the association of life-style factors with risk for abdominal aortic aneurysm among 29,133 male smokers 50-69 years of age, participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. During a mean follow-up of 5.8 years, 181 were diagnosed with ruptured abdominal aortic aneurysm or nonruptured abdominal aortic aneurysm plus aneurysmectomy. Risk for abdominal aortic aneurysm was positively associated with age [relative risk (RR) = 4.56, 95% confidence interval (CI) = 2.42-8.61 for > 65 vs 40 vs 160 vs 100 vs 6.5 vs 1.5 vs