Abstract 3428: Presence Of Renal Simple Cysts Is Associated With Increased Risk For Abdominal Aortic Aneurysm

Background : An increased prevalence of abdominal aortic aneurysm (AAA) has been demonstrated in patients with emphysema or inguinal hernia. Therefore, it has been suggested that the cause of AAA is a degenerative disorder of the connective tissue that can not always be explained by means of atherosclerosis. We hypothesized that the presence of renal simple cysts, another possible manifestation of connective tissue weakness, is associated with the increased risk for AAA. We compared incidence of renal simple cyst between the group of patients with AAA and healthy control group. Methods : We reviewed 279 patients with AAA and 1397 healthy control group who underwent abdominal computed tomography as a routine health screening from 1994 to 2006 in Samsung Medical Center. AAA was defined as an aortic diameter equal to or greater than 40 mm. Comparisons between groups were made for established risk factors for AAA. Results : AAA group has significantly more diabetes, smoking, history of anti-hyperlipidemic medication, hypertension, metabolic syndrome, higher systolic blood pressure than control group (all p values <0.0001). In the univariate analysis, prevalence of renal cysts ( p< 0.0001), bilateral renal involvement of cysts ( p< 0.0001), number of renal cysts ( p< 0.0001), and sum of sizes of renal cysts ( p< 0.0001) were significantly higher in AAA group as compared with control group. In the multivariate analysis, a person with renal cyst was more likely (OR: 4.379, CI: 3.402–5.636) to have AAA after adjustment for age, gender, smoking, hypertension, diabetes, HDL and LDL cholesterol. This relationship was similar for bilateral renal involvement of cysts, number of renal cysts, and sum of sizes of renal cysts. Neither a diameter nor an expansion rate of AAA was associated with the size of renal cysts. Conclusion: Patients with AAA have increased burden of renal simple cysts compared to healthy control group. The structural weakness predisposing for renal simple cysts may be associated with the initiation of AAA formation. Prospective study is needed to determine whether the presence of renal cysts can be considered as a risk factor of AAA.