TUESDAY, Dec. 20, 2005 (HealthDay News) -- A major U.S. study provides the best evidence yet that erectile dysfunction is a major warning sign of heart attack, stroke and other cardiovascular problems.
Men who had no problems with sexual function at the start of the seven-year study but developed erectile dysfunction later were 25 percent more likely to have a cardiovascular event such as a heart attack or stroke than those who did not, claims a report in the Dec. 21 issue of the Journal of the American Medical Association by physicians at the University of Texas Health Science Center at San Antonio.
The risk was 45 percent higher for men with erectile dysfunction at the start of the study, and was double for older men with the problem, the researchers reported.
"This is the study that everyone has wanted," said Dr. Melvyn Rubenfire, director of preventive cardiology at the University of Michigan. While other studies have pointed to a link between erectile dysfunction and cardiovascular risk, none have been as thorough or as large as this one, he noted.
The physicians followed more than 9,000 men in the Prostate Cancer Prevention Trial. From 1994 to 2003, the men were evaluated every three months for erectile dysfunction and cardiovascular disease, and careful watch was kept on their known cardiovascular risk factors, such as high blood pressure, high cholesterol, smoking and diabetes. The link between erectile dysfunction was independent of those risk factors, the report said.
The study was funded by grants from the National Cancer Institute.
"What is novel is the size and power of the study," said Rubenfire. "Also, it incorporated all of the classic risk factors. We've been saying to patients that this was likely to be the case, and now we have the data from this study that supports it."
In terms of medical practice, "if a patient presents with erectile dysfunction, I assume he has vascular disease," said Dr. Alan J. Bank, director of research at the St. Paul Heart Clinic. "We used to think that it was psychogenic, but only about 5 percent of the cases are."
The diagnosis calls for a vigorous effort against cardiovascular risk factors, Bank said, "trying to prevent future events, treating lipids more aggressively, treating blood pressure more aggressively, getting them to stop smoking, to exercise more."
The underlying cause of both erectile dysfunction and cardiovascular disease is a disruption of the activity of nitric oxide, a molecule produced in the blood vessel wall that enables arteries to expand, Bank said. Nearly two years ago, he published a study showing reduced nitric oxide function in the blood vessels of men with erectile dysfunction.
"The implications of this study are substantial," the Texas researchers wrote. "It is estimated that more than 600,000 men aged 40 to 69 years in the United States develop erectile dysfunction annually."
The study result "suggests that the initial presentation of a man with erectile dysfunction should prompt the evaluating physician to screen for standard cardiovascular risk factors," they said, and to take protective action against them.
The National Institute of Diabetes and Digestive and Kidney Diseases tells you more about erectile dysfunction.