Abdominal aortic aneurysm

Risk factors

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Although the ultimate causes for AAA are still unclear, the known risk factors are:

• Age and gender: AAA is most commonly encountered in older men. The condition is 2-5 times more common in men than women and the incidence increases with age in both sexes. In populations over age 60, estimates of prevalence range from 2% to 8%. AAA is uncommon in both men and women younger than 50 years of age.
• Smoking: is the single most important environmental risk factor and the more you smoke, the greater the risk. This is probably because the underlying cause for most AAA is atherosclerosis of the aorta, which is exacerbated by smoking. Research has shown that the prevalence of AAA in tobacco smokers is more than four times that of life-long non-smokers.
• Other cardiovascular risk factors: Some cardiovascular risk factors such as high blood pressure and abnormal cholesterol levels have been associated with AAA, whereas others, such as diabetes, have not.
• Ethnicity: AAA is diagnosed less frequently in Asians and African-Americans than individuals of European descent.
• Genetics: Genetic factors have a recognized impact on the development of AAA, with 15-20% of affected individuals reporting a family history of the condition. The lifetime risk of AAA in a first degree relative (parent, child or sibling) of a patient with AAA is 11-28% or 3-7 times that of the general population (with a lifetime risk of 4%).

Prevention and treatment

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The single most important prevention strategy is not to smoke and to stop smoking if you do. A healthy lifestyle in general is recommended, including regular exercise and maintenance of a normal weight.

The American College of Cardiology recommends a screening abdominal aortic ultrasound for men 60 years of age or older who are either siblings of AAA patients or have parents with AAA as well as for male smokers (current and former smokers) between 65 and 75 years of age.

In all patients with recognized AAA, blood pressure and cholesterol control is recommended and generally, surgical repair is planned for all aneurysms which are 5.5 centimeters (2.2 inches) and larger as well as all symptomatic AAA regardless of diameter. Urgency of surgical repair depends on the risk of rupture.

More information

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You can find out more information about AAA by talking with your doctor and visiting these Web sites:

• American Heart Association on abdominal aortic aneurysms
• American Academy of Family Physicians on abdominal aortic aneurysms
• Medline Plus article on abdominal aortic aneurysms
• National Heart Lung and Blood Institute article on aneurysms

Scientific references

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1. Diehm N, Dick F, Schaffner T, Schmidli J, Kalka C, Di Santo S, Voelzmann J, Baumgartner I. Novel insight into the pathobiology of abdominal aortic aneurysm and potential future treatment concepts. Prog Cardiovasc Dis. 2007 Nov-Dec;50(3):209-17. Review.
2. Helgadottir A, Thorleifsson G, Magnusson KP, et al. The same sequence variant on 9p21 associates with myocardial infarction, abdominal aortic aneurysm and intracranial aneurysm. Nat Genet. 2008 Feb;40(2):217-24.
3. Iribarren C, Darbinian JA, Go AS, Fireman BH, Lee CD, Grey DP.Traditional and novel risk factors for clinically diagnosed abdominal aortic aneurysm: the Kaiser multiphasic health checkup cohort study. Ann Epidemiol. 2007 Sep;17(9):669-78.
4. Kuivaniemi H, Platsoucas CD, Tilson MD 3rd. Aortic aneurysms: an immune disease with a strong genetic component. Circulation. 2008 Jan 15;117(2):242-52. Review.
5. Sakalihasan N, Limet R, Defawe OD. Abdominal aortic aneurysm. Lancet. 2005 Apr 30-May 6;365(9470):1577-89. Review.

This content was last reviewed on January 12, 2010.