NEW YORK (Reuters Health) – Problems with maintaining an erection may foretell heart trouble ahead for men with type 2 diabetes, two new studies show.

A number of past studies have found a connection between erectile dysfunction (ED) and heart disease.

But the new findings, published in the Journal of the American College of Cardiology, confirm that ED often precedes and predicts heart trouble.

This, say researchers, suggests that men with ED should be especially vigilant about controlling heart disease risk factors. In one study, Italian researchers found that among 291 men with type 2 diabetes, those who also had ED had twice the risk of suffering a heart attack, stroke or other cardiovascular complication over the next four years.

At the start of the study, all of the men had had evidence of "silent" heart disease – meaning they had plaque buildup in their arteries on imaging tests, but no heart disease symptoms, such as chest pain.

Having ED seemed to pinpoint those men who were at particular risk of a complication.

There was some good news as well, however: Taking cholesterol-lowering statins appeared to reduce the risks associated with ED, according to the researchers, led by Dr. Carmine Gazzaruso of the Clinical Institute "Beato Matteo" in Vigevano, Italy. In the second study, Hong Kong researchers found that among diabetic men with no indications of heart disease at the outset, those with ED were 58 percent more likely to die of heart disease, or have a heart attack or other non-fatal cardiac "event''.

"Erectile dysfunction is an important warning sign of future adverse heart events or even death," study chief Dr. Peter Chun-Yip Tong, of the Chinese University of Hong Kong, told Reuters Health.

The main reason, he explained, is that ED is an early manifestation of the blood vessel damage caused by diabetes and other risk factors for heart disease, such as high blood pressure. Tong recommended that all men with diabetes tell their doctor if they begin to have problems getting or maintaining an erection.

They can then have a comprehensive assessment of their cardiovascular risk factors – such as measurements of their blood pressure, cholesterol, waist size and kidney function – and work on getting those under control.

Indeed, the Italian study suggests that diabetic men with ED can cut some of their heart risks by using a statin.

Gazzaruso's team found that among patients with ED, those who were on a statin had a one-third lower chance of suffering a heart attack or other complication during the study.

There was also evidence that men taking a class of ED drugs called PDE-5 inhibitors, which includes Viagra, had lower heart risks. According to the researchers, this may reflect the fact that the drugs improve the function of the inner lining of artery walls. The bottom line, according to Tong, is that men with diabetes and ED should have all of their modifiable heart risk factors "identified early and treated aggressively''.