October 15 (HealthDay News) -- Women who smoke are eight times more likely to suffer a potentially fatal rupture of the body's largest artery, or require surgery to repair the weakening that can cause such a rupture, than nonsmokers.

That's the conclusion of the latest data from the Women's Health Initiative, the landmark trial most noted for the 2002 finding that hormone replacement therapy increases the risk of heart problems.

The new finding on the condition called abdominal aortic aneurysm comes from an analysis led by Dr. Frank Lederle, an internist at the Veterans Administration Medical Center in Minneapolis and a professor of medicine at the University of Minnesota.

"My particular interest is abdominal aortic aneurysm," Lederle said. "Most previous studies of it have been in men, so this is an opportunity to look at a very large study in women."

The aorta is the main artery carrying blood from the heart. An aneurysm is a weakening or ballooning of the blood vessel, a process that can take years to develop, often without symptoms. Some 15,000 Americans die each year when an abdominal aortic aneurysm ruptures, 40 percent of them women.

The link between smoking and aneurysm was not unexpected, Lederle said. "No one would have expected otherwise," he said. "There is a very strong association in men as well."

It is a strong relationship. Even women who gave up smoking had a fourfold higher incidence of rupture than women who never smoked.

What really interested Lederle was the finding that women with diabetes were less likely to have a rupture or surgery. It's not at all clear why that should be so, he said.

"Diabetes makes the arteries stiff, so that might be protective," Lederle said. "But other studies show that stiff arteries lead to abdominal aortic aneurysm. What we are going to need is a complete biochemical explanation."

The new study, published online Oct. 15 in the British Medical Journal, also found that hormone replacement therapy reduced the risk of abdominal aortic aneurysm.

"We expected to see it, but the relationship was surprisingly strong," Lederle said. "We certainly are not going to recommend that it [hormone replacement therapy] be used for that purpose."

The various findings "are of interest to guide future research," he added. "We would hope to develop a specific test for this condition."

Dr. David G. Neschis, a vascular surgeon and an associate professor of surgery at the University of Maryland, said the biggest impact of the new study "will be to raise awareness about the importance of abdominal aortic aneurysm in women. The focus has been on men, and so, it is not screened for as frequently in women."

"There are a huge number of undiagnosed aneurysms in women," Neschis added. "Most now are identified as incidental findings, when a woman has a CT scan of the gall bladder or magnetic resonance imaging for back trouble. Perhaps women should be screened more aggressively."

Screening is especially advisable for women who smoke, have high blood pressure or a family history of the condition, Neschis said. Age is also a factor, he said, since, "if you have it, it grows slowly over time."

SOURCES: Frank Lederle, M.D., professor of medicine, University of Minnesota, Minneapolis; David G. Neschis, associate professor of surgery, University of Maryland, Baltimore; Oct. 15, 2008, British Medical Journal, online