Introduction to Abdominal Aortic Aneurysm

Risk Factors for Abdominal Aortic Aneurysm

Though the exact cause of the formation and expansion of abdominal aortic aneurysms (AAA) is unknown, there are several factors which have been identified as placing an individual at higher risk for formation of an abdominal aortic aneurysm, including:

• Smoking - Smoking is considered the strongest risk factor for formation and expansion of abdominal aortic aneurysms and approximately 90% of patients with AAAs have smoked in the past or smoke currently. Smoking may increase the growth rate of an existing aneurysm by as much as 25% and is more predictive of expansion than high blood pressure. The rate of expansion for former smokers is slightly less than for current smokers. Estimates are that smoking 40 years or more increases the risk of abdominal aortic aneurysm formation six-fold and smoking 20 cigarettes a day increases the probability seven-fold. The risk of death resulting from rupture is also higher among current smokers. If an individual stops smoking, the risk of AAA formation slightly declines and if an abdominal aortic aneurysm is already present, the risk of rupture also declines slightly.

• Gender - abdominal aortic aneurysm occurs more frequently and at an earlier age in men than in women by a ratio of 3:1.

• Atherosclerosis - atherosclerosis is the hardening and narrowing of arteries. It is caused by the slow buildup of plaque (fatty deposits) on the inside of walls of the arteries. Lipid (fatty) deposits along the lining of the aorta weaken the walls leading to the formation of an aneurysm. Risk factors for atherosclerosis include:

  • smoking
  • elevated cholesterol
  • hypertension (high blood pressure)
  • family history of atherosclerosis
  • diabetes

• Older age - People 60 years of age or older are at higher risk for developing an abdominal aortic aneurysm than individuals who are younger than 60.

• Family history of AAA - genetics may play a role in the development of AAAs since first-degree relatives of patients, especially brothers of males with AAA, are at higher risk (estimates are up to 30%) for formation of an abdominal aortic aneurysm. In addition, family history of AAA increases the risk of rupture in the individual with abdominal aortic aneurysm.

• Hypertension - High blood pressure

• Chronic obstructive pulmonary disease (COPD)

• Previous vascular surgery

• Blunt abdominal injury (in children)