Women who smoke are significantly more likely to experience serious problems related to abdominal aortic aneurysms compared to those who do not smoke or have quit the habit, the results of a new study indicate.

An aneurysm is when a blood vessel becomes abnormally large or balloons outwards. It can pose a serious threat to health if it ruptures. The abdominal aorta is the large blood vessel that supplies blood to the abdomen, pelvis and legs.

According to US researchers, abdominal aortic aneurysms are more common in men but are more deadly in women, partly because aneurysms rupture at smaller diameters in women.

Until now, most studies of abdominal aortic aneurysm have focused on men and have included too few women to generate reliable information on the risk factors in women. A better understanding of the factors associated with aortic aneurysm may improve diagnosis and outcomes for women

The researchers assessed the potential risk factors for the rupture and repair of this type of aneurysm in over 161,000 postmenopausal women. The participants were followed for an average of 7.8 years.

There were 184 reported abdominal aneurysm events (repairs or ruptures) during the study and these were strongly linked to age and smoking. The study found that women who had ever smoked, currently smoked and the amount smoked, all contributed to the likelihood of having an abdominal aortic aneurysm.

Furthermore, smokers were four times more likely to have had an abdominal aortic aneurysm repair or rupture than women who had quit smoking and were eight times more likely than women who had never smoked.

The researchers also found that hormone replacement therapy (HRT) provided protection from abdominal aortic aneurysm events despite previous smaller studies reporting that oestrogen therapy alone may increase the risk.

They also found that women with diabetes were at a reduced risk of aneurysm events - a similar association has also been previously reported in men.

Increasing height, hypertension (high blood pressure), high cholesterol, and coronary and peripheral artery disease were also associated with an increased risk of aneurysm events.

Details of this study are published in the British Medical Journal. In an accompanying editorial, Prof Janet Powell from Imperial College London and Prof Paul Norman from the University of Western Australia, said that these findings emphasised the need for educating women about quitting smoking. They insisted that this must remain a public health priority.