Abstract 5024: Gender Differences in Aortic Wall Tension: Possible Role in the Prevalence of Abdominal Aortic Aneurysms
Background: Abdominal aortic aneurysm (AAA) is significantly more common in men than in women. The causes of gender differences in the prevalence of AAA are unknown. Increased aortic wall tension enhances the development and growth of AAA on aortic walls affected by inflammation, proteolysis, and apoptosis. We hypothesized that in a cohort of free-living individuals, aortic wall tension is higher in men than in women.
Methods: Aortic wall tension (AWT) was calculated using measurements from magnetic resonance images of the abdominal aorta, and systolic blood pressure (SBP) data of 2,519 participants of the Dallas Heart Study, a multiethnic, population-based probability sample. AWT was calculated from the mean aortic radius (MAR) and SBP according to Laplace’s formula (AWT = SBP × MAR). The Mann-Whitney test and linear regression analyses were used to evaluate gender differences in AWT, and the association of AWT with age.
Results: Most participants (54%) were women. Median (Interquartile range [IQR]) age was 44 (37–52) years for women and 43 (36 –52) years for men, P<.92. The median aortic wall tension was significantly higher in men compared with women (13 [IQR], 11.5–14.7 vs. 11.1 [IQR] 9.5–13.0) × 105 Dynes/cm2, respectively; P<.0001. AWT values increased with age in both sexes (P<.001) and were uniformly greater at all ages in men than in women.
Conclusions: In this population-based sample, aortic wall tension is greater in men than in women at all ages. This hemodynamic difference may play a role in the disproportionately higher prevalence of AAAs among men.