On the association between abdominal aorta and basilar artery diameters: a population-based study in community-dwelling older adults

Introduction: Information on the relationship between the diameters of the abdominal aorta (AA) and the basilar artery (BA) is limited. Using the Atahualpa Project cohort, we aimed to assess this association in Atahualpa residents aged ≥ 60 years. Materials and methods: Atahualpa residents aged ≥ 60 years underwent abdominal ultrasound and MRA of intracranial vessels. The independent association between both arterial diameters was estimated in a generalized linear model adjusted for demographics, cardiovascular risk factors, the presence of a fetal-type Circle of Willis, and severity of white matter hyperintensities. Fractional polynomials were fitted to model the relationship between AA and BA diameters. Results: The mean age of 277 participants was 69.5 ± 7.7 years (61% women). The mean AA diameter was 19.8 ± 3.3 mm, and the mean BA diameter was 3.1 ± 0.7 mm. The mean diameters of both arteries were significantly higher in men than in women. Locally weighted scatterplot smoothing showed a non-linear relationship between both arterial diameters. Fractional polynomial models showed that AA and BA diameters had a significant non-linear association in men (p = 0.005), but not in women (p = 0.315). When sex was excluded from a generalized linear model, the relationship between both arterial diameters became significant (p = 0.017). Conclusion: In this population of community-dwelling older adults, the relationship between AA and BA diameters was confined to men. The finding of a large AA diameter in men should prompt the investigation of the intracranial vasculature because of the possibility of BA ectasia.