Getting to The Heart Of ED
Tuesday, March 13, 2007
There are plenty of reasons for men to keep their hearts healthy, but one hits below the belt: Our sex lives may depend on it. More than one in six men nationwide says he sometimes or always has difficulty with erections, according to a study published last month in the American Journal of Medicine. And poor cardiovascular health is often to blame.
Another way of viewing the problem is that more than 18 million U.S. men older than 20 have erectile dysfunction, or ED -- at least according to one definition. (More on that in a moment.)
"In an earlier era, [ED] was thought to be more of a psychological issue than a physical one," said Elizabeth Selvin, the Johns Hopkins University epidemiologist who led the new study involving about 2,100 men selected to form a cross section of male America. "We're realizing now that a huge proportion of ED cases reflect vascular disease."
Urologist Christopher S. Saigal of the University of California at Los Angeles, who reported a similar frequency in a separate study published last year in the Archives of Internal Medicine, agreed, saying, "ED is a manifestation of what's happening in the rest of the cardiovascular system."
Together, the two studies provide the most comprehensive look to date on the prevalence of ED. Indirectly, the studies also offer further evidence that lifestyle changes, such as weight loss, regular exercise and smoking cessation, may offer an alternative to drug treatment.
In the normal male sexual response, sensory or mental stimulation causes blood to fill the corpora cavernosa, a pair of tubular structures that run the length of the penis. The relaxing of smooth muscle tissue helps trap blood in the organ, sustaining an erection.
Normal aging is thought to play a role in ED, perhaps by helping to make tissues less efficient in transporting blood. Of men 70 and older, 70 percent report having erectile dysfunction, compared with just 5 percent of 20- to 39-year-old men, Selvin found in her study.
Other problems can compound the effects of age: Alcohol abuse, certain drugs (many antidepressants, antihistamines and blood pressure medications) and nerve damage from prostate surgery, for example, can all interfere with erections.
But ED is most often linked to such risk factors for heart disease as smoking, diabetes, obesity, high blood pressure and high cholesterol.
"A lot of these conditions affect the circulation, particularly in the penis," limiting blood flow to the organ, said Arthur L. Burnett, a urologist at the Johns Hopkins University School of Medicine who collaborated with Selvin on her study.
Half of diabetic men, for example, have erectile dysfunction, according to both the Hopkins researchers and Saigal's earlier work. At any age, sedentary men are two to four times as likely to have ED as more physically active men.
Past studies that explored the prevalence of erectile dysfunction yielded estimates ranging from 8 percent (in a 1999 study of men age 18 to 59) to 52 percent (in a 1994 study of Massachusetts men age 40 and older), Selvin noted. Inconsistencies in how different studies have defined ED account for some of this variation.