A popular treatment for erectile dysfunction may help a man's heart, and men with high blood pressure are at risk for impotence, two new studies show.

"Middle-aged and older males are more likely to have erectile dysfunction, and this same group of men are more likely to not have their blood pressures under control, says Daniel T. Lackland, DrPH, professor of epidemiology and medicine at the University of South Carolina in Charleston.

Greek researchers reported at the American Society of Hypertension's 20th Annual Scientific Meeting and Exposition that treating impotent men who have high blood pressure with Viagra reduces blood vessel stiffness — a marker of atherosclerosis and a risk factor for heart disease.

"The studies show that men with erectile dysfunction should have their blood pressures checked and then controlled. The other shows that just the mere treatment of ED may improve aortic stiffness," says Lackland.

About 65 million Americans have high blood pressure, a risk factor for heart disease, stroke, and kidney disease. And it is estimated that 20 million American men have some degree of erectile dysfunction.

The Connection Between Blood Pressure and ED

Greek researchers say blood pressure and ED are not only connected, but for men with high blood pressure, the risk of erectile dysfunction is more than twice as high as men with normal blood pressure.

"Our research determined that for men with high blood pressure, the chances that they may be at risk for or have erectile dysfunction dramatically increases," said Michael Doumas, MD, from the fourth department of internal medicine at the University of Athens in Greece.

The study involved 358 hypertensive men aged 31-65. The men were asked to complete a questionnaire that evaluated erectile dysfunction according to the International Index of Erectile Function. The researchers compared them with a group of men without high blood pressure.

ED and Prehypertension

Thirty-five percent of men with high blood pressure had some degree of erectile dysfunction, and 9.2 percent of those reported severe impotence.

Of the men with high blood pressure:

—89 had never taken antihypertensive treatment. In these men, 20 percent had erectile dysfunction.
—160 were on medication to control blood pressure and 36 percent had erectile dysfunction.
—107 were taking two or more medications to control blood pressure and 47 percent of these men had erectile dysfunction.

By contrast, 14.1 percent of men without high blood pressure had some degree of the condition and 1.5 percent of these had severe impotence.

Even patients with prehypertension — those men who just had high-normal blood pressure — had higher rates of erectile dysfunction. This suggests that men in this population should be given special attention for risk of hypertension, Doumas says.

Viagra May Aid Blood Vessel Walls

In a second study presented at the meeting, Charalambos Vlachopoulos, MD, of the first department of cardiology at Athens Medical School in Greece, examined the long-term effects of Viagra on blood vessel stiffness of the body's main artery.

"The drug has a beneficial long-term effect on aortic stiffness, a risk factor for isolated systolic hypertension, heart attack, stroke, and coronary artery disease," he said at a news conference.

Vlachopoulos said that using Viagra to treat hypertensive men with erectile dysfunction may change the vessel wall, increasing its elasticity.

"We are still unsure of the mechanism, but [Viagra] may be stimulating the elastin or collagen in the vessel wall."

Men with ED and those suffering from atherosclerosis share a common defect: blood vessel wall dysfunction, he said. The cells that cover the inner lining of blood vessels secrete important substances, such as nitric oxide, that help control vascular tone and the ability of the vessels to dilate.

In the study, 11 men with ED received either 100 milligrams of Viagra daily or a placebo for more than two weeks. The two groups were then switched.

Blood flow in a vessel of the neck was measured at the study's start and one and two weeks later. Pulse-wave velocity — a measurement of blood flow — was taken 24 hours after the dose of Viagra.

The researchers found that arterial stiffness decreased for men taking Viagra.

"This lasted well after the acute effects of the drug had worn off," he said. "This could have important implications on the overall cardiac risk of these men."

While the study is promising, Vlachopoulos says that more in-depth research is needed.

By Linda Little, reviewed byBrunilda Nazario, MD


SOURCES: American Society of Hypertension 20th Annual Scientific Meeting and Exhibition, San Francisco, May 14-18, 2005. Michael Doumas, MD, fourth department of internal medicine, University of Athens, Greece. Charalambos Vlachopoulos, MD, first department of cardiology, Athens Medical School, Greece. Daniel T. Lackland, DrPH, professor of epidemiology and medicine, University of South Carolina, Charleston.