A recently published study found that about 18 percent of U.S. men aged 20 and over suffer from erectile dysfunction.

Erectile dysfunction is the inability to attain an adequate penile erection for satisfactory sexual activity is strongly linked to a sedentary lifestyle.

Not surprisingly, the condition was most common in older men; however, there was a strikingly high prevalence in men with diabetes and high blood pressure.

Epidemiologist Elizabeth Selvin of Johns Hopkins University in Baltimore, Maryland, who led the study said: "This really means that staying active, moving more and eating less, and staying healthy, in addition to being good for your cardiovascular health may also be good for your sexual health. It's just another reason to get off the couch and exercise.”

The study in the American Journal of Medicine sought to get a sense of the prevalence of erectile dysfunctio, in what Selvin called "the post-Viagra era."

The U.S. government approved Viagra in 1998 as the first pill for erectile dysfunction. The arrival of Viagra not only provided a treatment option for this condition, but boosted awareness of the formerly taboo subject and made it more acceptable to discuss.

The study estimated that 18.4% of U.S. men age 20 and older (about 18 million) have the condition. Among those aged 20-39, 5.1% suffered; ages 40-59, 14.8%; ages 60-69, 43.%; and age 70 and older 70.%.

The study also found that nearly 90% of men with erectile dysfunction also had risk factors for cardiovascular disease, including diabetes, high blood pressure, poor cholesterol levels or were smokers.