The role of cardiovascular risk factors and atherosclerosis in the aetiology of abdominal aortic aneurysms is not well understood. The aim of this study was to determine the association between atherosclerosis and aortic aneurysm in the general population and the extent to which cardiovascular risk factors might increase the risk of aneurysm independently of an effect on atherosclerotic disease.
In the Edinburgh Artery Study, 1592 men and women aged 55–74 years were followed prospectively over a period of 5 years. Forty subjects were identified as having an abdominal aortic aneurysm and, for each, five controls were randomly selected. Cases showed a higher prevalence of cardiovascular disease (P≤0·001) and had a lower ankle brachial pressure index (P≤0·01). Current and recent ex-cigarette smokers had an increased risk of aortic aneurysm compared with long time ex-smokers and never smokers (odds ratio 3·08, 95% CI 1·53 to 6·21 Adjustment for concurrent atherosclerotic disease reduced the odds ratio to 2·63 (95% CI 1·26 to 5·45). The risk of aortic aneurysm was not related to elevation in diastolic blood pressure or in serum cholesterol.
These findings indicate that atherosclerotic disease is associated with risk of aortic aneurysm in the general population. In addition, cigarette smoking appears to have a direct effect on the risk of aortic aneurysm which is independent of atherosclerosis.