Sex-specific reference values and determinants of infra-renal abdominal aortic diameter among women and men from general population

Abstract

Abstract Introduction Abdominal aortic diameter has shown to be a marker of adverse cardiovascular outcomes. Among the non-aneurysmal populations, studies regarding abdominal aortic diameter normal reference values are sparse. Moreover, data regarding the associations between cardiovascular risk factors and aortic diameter among men and women are limited. Purpose To establish age- and sex-specific distribution of the infra-renal abdominal aortic diameters among non-aneurysmal older adults from the general population and to investigate the associations between cardiovascular risk factors and aortic diameters in men and women. Methods From a population-based cohort, 4032 participants (mean age, 67.2 years; 60.4% women) with infra-renal diameter assessment and without history of cardiovascular disease were included. Mean and quantile values of diameters were calculated in different age groups. Multiple linear regression analysis was used to detect the association of cardiovascular risk factors with diameters in men and women. Results The mean crude diameter was larger in men [mean (SD): 19.5 (2.6) mm] compared to women [17.0 (2.4)mm] but after adjustment for body surface area (BSA), the differences were small. There was a non-linear relationship between age and diameter (p<0.001). After 66 years of age, the increase in diameter with increasing age was attenuated. After age 74 years in women and 71 years in men, the relationship between age and infra-renal aortic diameter was no longer statistically significant (Figure). Waist [standardized β (95% CI): 0.02 (0.0–0.04) in women and 0.03 (0.01–0.06) in men] and diastolic blood pressure [0.04 (0.02–0.05) in women and 0.02 (0.0–0.04) in men] were the risk factors for diameters in both sexes. Body mass index [0.02 (0.01–0.09)], systolic blood pressure [−0.01 (−0.02 to −0.01)], smoking status [0.21 (0.02–0.39)], cholesterol [−0.19 (−0.29 to −0.09)], and lipid-lowering medication [−0.47 (−0.71 to −0.23)] were significantly associated with aortic diameter only in women. Conclusion The differences in the crude abdominal aortic diameter between women and men diminished after taking into account the BSA. The abdominal aortic diameter increased steeply with advancing age and up to 66 years of age. However, after 74 years in women and 71 years in men, the diameter values reached a plateau. We also observed sex differences in the associations of cardiovascular risk factors with abdominal aortic diameter. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Netherlands Organization for the Health Research and Development (ZonMw); the Research Institute for Diseases in the Elderly (RIDE)