Prevalence and risk factors for abdominal aortic aneurysms in older adultswith and without isolated systolic hypertension

An association between abdominal aortic aneurysm (AAA) and atherosclerotic disease has been recognized and may be due to shared risk factors. A consis tent relation between blood pressure and AAA has not been found, AAA was co mpared between those with and without isolated systolic hypertension (ISH) and prevalence of aortic atherosclerosis wets evaluated. Abdominal aortic u ltrasound was performed in 266 people, 143 with ISH and 123 age-similar con trols. AAA was defined as an infrarenal aortic diameter of greater than or equal to 3.0 cm or on infrarenal-to-suprarenal diameter ratio of greater th an or equal to 1.2. The average age of participants was 73 years. Overall p revalence of AAA was 9.4%, 11.9% in those with ISH and 6.5% among normotens ives (p = 0.134). Multivariate analysis revealed male gender (p <0.001), hi gher low-density lipoprotein (p <0.001), higher pulse pressure (p = 0.032), and current smoking (p = 0.012) to be independent predictors of AAA. When evaluating aortic atherosclerosis, those with AAA had significantly larger diameters of the iliac arteries along with greater intima-media thickness o f the iliac arteries. Those with and without aneurysms had a similar preval ence of plaque (89% to 96%), but measured plaques tended to be larger among those with than without AAA (p <0.001). Progression of AAA after 1 year wa s observed in 8 participants, with a mean diameter change of 3.42 mm. AAA w as found to be independently associated with pulse pressure but not with sy stolic blood pressure. Patients with AAA also had greater wall thickness an d greater diameter of the iliac arteries, which are probably associated wit h the underlying disease process. (C)1999 by Excerpta Medica, Inc.