In a study of men with type 2 (adult-onset) diabetes, those with erectile dysfunction (ED) had an eight-fold risk of having undiagnosed heart disease, Italian researchers found.

"Erectile dysfunction was significantly more frequent" in diabetic men later discovered to have "silent," or symptomless, heart disease, said lead researcher Dr. Carmine Gazzaruso, an internal medicine specialist from Maugeri Foundation Hospital, Pavia, Italy.

In their study, the researchers tracked the prevalence of ED in 133 diabetic men with heart disease diagnosed by angiogram, and compared it to rates of ED in 127 diabetic men without heart disease. Both groups also underwent EKGs and cardiac stress tests, according to the report published in the June 21 online edition of Circulation: Journal of the American Heart Association.

Gazzaruso's team discovered that about a third (33.8 percent) of patients with silent coronary artery disease had ED. On the other hand, just 5 percent of men without heart disease were affected by erectile problems.

In diabetic men, ED may serve as a "red flag" that doctors should test for underlying cardiovascular disease, even in the absence of typical symptoms, Gazzaruso said. Screening all men with type 2 diabetes without obvious heart disease symptoms "is not justified," he said, because "there is low probability of finding significant coronary artery disease" in most of these patients. However, ED could prove a valuable marker in pinpointing those men likely to have heart trouble.

"Indeed, to find subjects with silent coronary artery disease is very important," Gazzaruso explained, since early diagnosis means earlier treatment and reduced risk for heart attack.

Gazzaruso recommended that a cardiovascular evaluation by a doctor should be done before starting drug therapy for ED. This is especially important for diabetic patients with additional cardiovascular risk factors, such as high blood pressure and high cholesterol, he said.

Although men often have a tough time admitting they have erectile problems, in this case full disclosure between a man and his doctor could be a life-saver. "Considering the possible association of ED with silent coronary artery disease, patients should not deny the presence of ED when it is present," Gazzaruso said.

"On the contrary, the patient should inform his physician of his ED. In this way, he can avail himself of new, effective treatments for ED and also provide his physician another tool to establish more precisely his global cardiovascular risk."

But Dr. David D. Gutterman, a professor of medicine and physiology at the Medical College of Wisconsin, believes a large number of diabetic men should undergo routine cardiovascular testing, regardless of whether they have erectile difficulties.

"Although twice as many patients with ED had silent coronary artery disease as without ED, the incidence of coronary artery disease in all patients with diabetes in the study was about 50 percent," he pointed out.

"If I were to interpret the data from these particular patients, I would conclude that all diabetics should be screened for silent coronary artery disease, not just those with ED," he added. "The study has enough weaknesses to make me hesitant to change my practice based on the findings."

Dr. Eugene Barrett, a professor of internal medicine at the University of Virginia and an expert in diabetes, added, "This population is one who would likely be recommended to have stress testing performed even in the absence of erectile dysfunction -- middle-aged diabetic patients who smoke and have a high prevalence of high blood pressure."