Smokers Twice as Likely to Develop Aortic Aneurysms

A new study suggests that smokers hold almost double the risk of developing an abdominal aortic aneurysm (AAA) than the general population, but they can lower their risk by quitting.

Researchers at the University of Minnesota (UMN; Minneapolis, USA), Emory University (Atlanta, GA, USA), and other institutions conducted a study involving 15,792 participants over the age of 45 recruited in the U.S. national Atherosclerosis Risk in Communities (ARIC) study between 1987 and 1989, and followed up through 2013. The researchers examined lifetime risk of AAA and prospectively assessed the association between midlife cardiovascular risk factors and AAAs.

The results showed that after 22 years of follow-up, 590 cases of a ruptured, surgically repaired, or clinically diagnosed asymptomatic AAA were identified. A further 75 cases of asymptomatic AAA were detected by an ultrasound screening. Analysis revealed that lifetime risk of an AAA were 1 in 17 among all study participants; 1 in 9 among current smokers; 1 in 9 among those in the top third of smoking pack-years, whether a current or former smoker; and 1 in 12 among current female smokers.

The researchers also found that short-term quitters (3-8 years) still had an approximately 2.6-3.5 fold increased risk for both clinical and asymptomatic AAA in the next 15 years compared to never smokers, representing a lifetime risk 6.6% higher than long-term quitters. Findings also showed that being older, white, or having high levels of low-density lipoprotein (LDL) cholesterol also increased the risk of AAA. The study was published on November 10, 2016, in Arteriosclerosis, Thrombosis and Vascular Biology.

“Our study quantified the lifetime risk of an AAA and found that it was far from trivial for smokers; and we quantified the benefit of quitting smoking, which turns out to be substantial,” said lead author Weihong Tang, PhD, MD, of the University of Minnesota. “Women who currently smoke have a similar risk as men who quit smoking; and yet, the task force does not recommend screening these women. This is important data that physicians and health policy makers should be aware of.”

AAA is the localized dilatation of the abdominal aorta exceeding the normal diameter by more than 50%, and is the most common form of aortic aneurysm; approximately 90% occur below the kidneys. The aneurysms can extend to include one or both of the pelvic iliac arteries. The major complication of AAA is rupture, which is life-threatening, as large amounts of blood spill into the abdominal cavity, and can lead to death within minutes. Mortality of rupture repair in the hospital is 60-90%.

Related Links:
University of Minnesota
Emory University