Abdominal Aortic Diameter and Vascular Atherosclerosis: The Multi-Ethnic Study of Atherosclerosis

Abstract

Objectives To gain insight into early mechanisms of aortic widening, we examined associations between the diameter of the abdominal aorta (AD) and cardiovascular disease (CVD) risk factors and biomarkers, as well as measures of subclinical atherosclerosis, in a multi-ethnic population. Design Cross-sectional cohort Methods A total of 1926 participants (mean age 62, 50% women) underwent chest and abdomen scanning by computed tomography, ultrasound of the carotid arteries, and CVD risk factor assessment. AD was measured 5 cm above and at the bifurcation. Results In a model containing traditional CVD risk factors, biomarkers and ethnicity, only age (standardized β=0.97), male sex (β=1.88), body surface area (standardized β=0.92), current smoking (β=0.42), D-dimer levels (β=0.19) and hypertension (β=0.53) were independently and significantly associated with increasing AD (in mm) at the bifurcation; use of cholesterol-lowering medications predicted smaller AD (β=-0.70) (P<.01 for all). These findings were similar for AD 5 cm above the bifurcation with one exception: compared to Caucasian-Americans, Americans of Chinese, African and Hispanic descent had significantly smaller AD 5 cm above the bifurcation (β's= -0.59, -0.49, and -0.52, respectively, all P<.01), whereas AD at the bifurcation did not differ by ethnicity. Physical activity, alcohol consumption, diabetes and levels of IL-6, CRP and homocysteine were not independently associated with AD. Higher aortic and coronary artery calcium burden, but not common carotid artery intima-media thickness, were independently, but modestly (β=0.11 to 0.19), associated with larger AD. Conclusions Incremental widening of the aortic diameter shared some, but not all, risk factors for occlusive vascular disease.

The cardiovascular and prognostic significance of the infrarenal aortic diameter

“…8 The negative association between diabetes and both AAA presence and expansion has also been reported with aortic diameter, 18,23 although this was not confirmed in a recent study. 8 Even among nondiabetic individuals, there seems to be a significant inverse correlation between fasting glucose concentration and aortic diameter throughout its range. 18 The mechanism responsible for the reduction of aortic dilation by hyperglycemia is unknown but has been attributed to a combination of enhanced deposition and reduced degradation of matrix as well as the consequences of advanced glycation product deposition in the aortic wall.…”

“…6,8 As with AAAs, white people seem to have larger aortas than all other ethnic groups. 8 The negative association between diabetes and both AAA presence and expansion has also been reported with aortic diameter, 18,23 although this was not confirmed in a recent study.…”

“…6,8 As with AAAs, white people seem to have larger aortas than all other ethnic groups. 8 The negative association between diabetes and both AAA presence and expansion has also been reported with aortic diameter, 18,23 although this was not confirmed in a recent study. 8 Even among nondiabetic individuals, there seems to be a significant inverse correlation between fasting glucose concentration and aortic diameter throughout its range.…”

“…6,14,[17][18][19][20][21] Some studies suggest that body surface area is more strongly associated with diameter than the other measures of body size. 8,13,22 Gorter et al 20 reported that, among participants with clinically evident arterial disease in the Second Manifestations of Arterial Disease Trial, both BMI and extent of intra-abdominal fat were associated with increased aortic diameter.…”

Insulin resistance and endothelial function in children and adolescents

“…Hystopathological and post-mortem evaluation of children and adolescents demonstrated that abdominal aorta is the place where the total number of atherosclerotic lesions happened more than the coronary arteries, thus underlining the importance of the evaluation of the aorta since early stages of life. The Multi-Ethnic Study of Atherosclerosis (MESA) study pointed out that infrarenal abdominal aorta diameter was directly related to the most important cardiovascular risk factors which are able to account for the appearance of occlusive vascular diseases [30]. Nevertheless, this study was validated in a population of 1926 adult subjects (age from 44 to 84 years), not considering a younger population.…”