Abstract P241: Correlates of Abdominal Aortic Diameters Among Persons without Abdominal Aortic Aneurysms: The Atherosclerosis Risk in Communities (ARIC) Study

Abstract

Background: Evidence from cohort studies has demonstrated that advanced age, male gender, white race, greater height, smoking, hypertension and dyslipidemias for abdominal aortic aneurysm (AAA). However, the associations of these risk factors with increased abdominal aortic diameters among persons without AAA have not been extensively examined in prospective studies; such evidence may help further with AAA prevention strategies. Methods: We included participants of the ARIC cohort who underwent abdominal ultrasound in 2011-2013. We excluded participants with prior clinical AAAs identified from hospital discharge codes, death codes, Medicare outpatient claims, or an infrarenal abdominal aortic maximum diameter ≥ 3 cm in the ultrasound exam. Risk factors, when available, across five visits during 1987-2013 were analyzed as the weighted average, weighting by the number of years exposed, in logistic regression models to examine the relationships with risk of being in the highest quartile of infrarenal abdominal aortic maximum diameter (≥2.2 cm). The models were adjusted for attrition by using inverse probability weighting. Results: Of 5,671 participants included in the analysis, 40.4% were men and 22.1% were blacks. After adjustment for age, sex, race, and ARIC field center, greater smoking pack years and height were associated with great abdominal aortic diameter (odds ratio Highest Quintile vs. Lowest Quintile: 1.66 [95% CI: 1.41, 1.96; P for linear trend: 0.027] for smoking pack years, and 2.61 [95% CI: 1.99, 3.43; P for linear trend: <0.001] for height), and high-density lipoprotein cholesterol was negatively associated with great abdominal aortic diameter (odds ratio Highest Quintile vs. Lowest Quintile: 0.69 [95% CI: 0.55, 0.87; P for linear trend: 0.007]). Men were more likely (odds ratio: 4.15 [95% CI: 3.67, 4.69]; P <0.001) to be in the highest quartile of abdominal aortic diameters than women; and the association persisted after further adjusting for height and smoking pack years (odds ratio: 2.34 [95% CI: 1.94, 2.84]; P <0.001). Other established AAA risk factors were not associated with abdominal aortic diameter. Conclusions: Among well-established AAA risk factors, male gender, cigarette smoking and greater height were positively associated while high-density lipoprotein cholesterol was inversely associated with greater abdominal aortic diameters among persons without AAA in this large population-based cohort.