Men who smoked more than 20 cigarettes daily had 60 percent higher risk of erectile dysfunction, compared to men who never smoked. The data showed a dose-related impact of smoking: the risk of erectile dysfunction was lower in men who smoked fewer cigarettes, but still increased compared to non-smokers.
The effect of smoking remained significant after considering other factors known to affect erectile function such as age, blood pressure, cholesterol levels, diabetes and body mass index (BMI).
"This is not the first study to document an association between cigarette smoking and erectile dysfunction," says Jiang He, M.D., Ph.D., Steward Associate Professor of Epidemiology and Medicine at Tulane University School of Public Health and Tropical Medicine in New Orleans. "However, our study is very unique because it is able to adjust for important confounders, such as blood pressure, serum cholesterol, and diabetes."
Erectile dysfunction is often associated with atherosclerosis, the build-up of wax-like plaque that obstructs blood flow through vessels. Smoking is a well-recognized risk factor for cardiovascular disease and studies have shown there are strong parallels and shared risks among smoking, coronary artery disease, atherosclerosis, and erectile dysfunction, says He.
Researchers examined data on 4,764 Chinese men (average age 47) involved in the InterASIA study, a national cross-sectional health survey conducted during 2000-2001. The survey included questions about respondents' current smoking status and history and quality of sexual relations. All men reported having sexual relations within the past six months.
Survey respondents were defined as current smokers if they were smoking at the time of the survey and had smoked at least 100 cigarettes in their lifetime. Former smokers were defined as having smoked more than 100 cigarettes in their lifetime but were not smoking at the time of the survey.
The average blood pressure and cholesterol values for the men were within normal ranges, and the average body mass index (BMI, an indicator of weight and body size) indicated the men were not overweight as a group. Of the survey respondents, 62.1 percent were current smokers, and 9.5 percent were former smokers.
Overall, 14.6 percent of the men experienced erectile dysfunction. Current and former smokers had identical rates of 15.1 percent, and the rate among men who had never smoked was 11.5 percent. After statistically accounting for other erectile function influences, researchers found that current smokers had a 31 percent higher risk for dysfunction compared to men who had never smoked. A similar difference was seen in former smokers, who had a 35 percent higher risk.
"We did not see a difference between current and former smokers," He says. "However, the number of former smokers is small in this study."
Focusing on current smokers, researchers evaluated the impact of increasingly heavy cigarette smoking on erectile dysfunction. Men who reported smoking fewer than 10 cigarettes a day had a 16 percent higher risk of erectile dysfunction, compared to men who had never smoked. The risk increased to 36 percent in men who reported smoking 11-20 cigarettes daily and was 60 percent higher in men who smoked more than 20 cigarettes (one pack) daily.
The findings build on and strengthen data from other studies suggesting that cigarette smoking is a risk factor for erectile dysfunction.
"These findings provide additional information that smoking has important adverse health effects," says Robert O. Bonow, M.D., president of the American Heart Association. "This gives male smokers another reason to kick the habit, and provides another area of emphasis and education for smoking cessation programs."
Co-authors are Dongfeng Gu, M.D.; Xigui Wu, M.D.; Xiufang Duan, M.D.; Kristi Reynolds, M.P.H.; Paul Muntner, Ph.D.; Paul K. Whelton, M.D.; Robert F. Reynolds, D.Sc.; and Dale B. Glasser, Ph.D.
For information March 5-8 call
Carole Bullock or Darcy Spitz at the
Fontainebleau Hilton Resort in Miami 305-674-4740