March 6, 2003 -- Guys, if some of you wonder what's wrong in the bedroom, here's a clue. If you want to smoke in the bedroom, quit smoking. New research adds to the evidence that smoking may be a major cause of erectile dysfunction.

A study looking at the impact smoking has on a man's ability to get an erection was reported today at the American Heart Association's annual Conference on Cardiovascular Disease Epidemiology and Prevention being held in Miami.

"This is not the first study to document an association between cigarette smoking and erectile dysfunction," says researcher Jiang He, MD, PhD, an epidemiologist with Tulane University School of Public Health and Tropical Medicine in New Orleans, in a news release. But this study is unique in that it looks at other factors associated with erectile dysfunction - also known as impotence -- and was able to adjust for these factors, he says.

Both smoking and erectile dysfunction have often been associated -- individually -- with plaque build-up in the arteries, called atherosclerosis. The plaque obstructs blood flow through vessels, causing a host of circulatory problems throughout the body, such as erectile dysfunction.

In this study, researchers examined data on 4,764 Chinese men -- average age 47 -- who completed a health survey. Smoking history and quality of sexual relations were among the questions.

Among the findings:

Men who smoked more than 20 cigarettes daily had a 60% higher risk of erectile dysfunction, compared to men who never smoked.

15% of the past and present smokers had experienced erectile dysfunction.

Men who currently - and formerly -- smoked were about 30% more likely to suffer from impotence.

Among men who had never smoked, 12% had erection problems.

It's yet another reason for smokers to kick the habit, says Robert O. Bonow, MD, AHA president, in a news release.