Objective:
Abdominal aortic aneurysms are defined as a 50% or greater increase in infrarenal aortic diameter (IAD). However, normal IAD has not been defined for all ethnic groups as minorities have been underrepresented in most studies. The aim of the study was to assess ethnic differences in IAD and infrarenal aortic area (AoA) adjusting for the effects of age, gender and body size in the general population.
Methods:
Participants (2,515) in a population based study underwent high-resolution magnetic resonance imaging (MRI) of the abdominal aorta. Analyses of variance and multiple regression analyses were used to assess the relationship between race/ethnicity, age, gender and body size and IAD and aortic area. Subjects with AAA detected by MRI (defined as IAD ≥ 3.0 cm) were excluded from the analysis.
Results:
Decreasing age, female sex, Hispanic ethnicity, and lower height were independent predictors of reduced IAD by multivariate linear regression (all
P
< 0.001). Of these, female sex and Hispanic ethnicity were the factors more strongly associated with aortic size. Female sex was associated with 0.27 cm reduction in IAD and Hispanic ethnicity with 0.39 cm reduction in IAD. Similarly, decreasing age, female sex, Hispanic ethnicity, and lower height were independent predictors of reduced AoA. Female sex was associated with a 51 cm
2
reduction in AoA and Hispanic ethnicity with 11.1 cm
2
reduction in AoA. Although Hispanics had higher BMI than blacks and whites (
P
=.01), and lower height values than blacks and whites (P<.0001), IADs and AoAs were consistently lower among Hispanics.
Conclusions:
Ethnic differences exist in infrarenal aortic diameter. Despite larger body size, Hispanics have significantly lower IAD than blacks and whites in the general population. The reduced aortic size in Hispanics suggests that the thresholds for abdominal aortic aneurysm diagnosis, rupture and repair may be lower and need to be established.
Removal of metastatic nodes para-aortic area
