A study found that asthma activity increased the risk of abdominal aortic aneurysm (AAA) by 45 percent in men aged 65 to 74. In a separate group of AAA patients aged 50 and above, a recent diagnosis for asthma is linked to an aortic aneurysm rupture risk by almost two-folds.

An AAA is a weak link in main artery. A weak aorta can form a bulge that can rupture and cause extreme bleeding. Male asthma patients were twice as likely to suffer from AAA, while the risk is much lower in female asthma patients. Findings also showed that usage of asthma medication in the previous six months was associated with a 45 percent risk increase for AAA.

"People with abdominal aortic aneurysm who were diagnosed with asthma within the past year had more than a 50 percent greater risk of ruptured aneurysms than those without asthma," said Brigham and Women's Hospital's Guo-Ping Shi, the study's lead researcher.

Shi and colleagues utilized the data taken from two national health groups in Denmark. The first group had data on almost 16,000 men and women who were 50 years old and above. Nearly 4,500 senior adults had AAA. The second group had data on 619 AAA patients and their smoking habits.

The researchers pointed to immunoglobulin E or IgE, an inflammation-related protein, as the cause of the association. The body makes IgE as a response to substances that cause an allergic reaction. This protein stiffens the arteries which could result in an aneurysm.

The study was published in the journal Arteriosclerosis, Thrombosis, and Vascular Biology on Feb. 11. Shi said that the recent study only highlighted the link between aneurysm, asthma and ruptured aneurysm. The findings do not prove that the respiratory condition causes either aneurysm or a rupture.

Senior men who carry risks factors such as high blood pressure and cholesterol, smoking, emphysema and obesity are more likely to have suffer from AAA. This condition can be life-threatening. Shi suggested that men aged 50 and above should be screened for aneurysms through non-invasive ultrasound and undergo operation to remove the aneurysm, if necessary.

"Older patients with asthma should be screened for AAA, and patients with established AAA should be monitored closely for signs of growth," added Shi.