THURSDAY, April 15, 2010 (HealthDay News) -- An Italian study of men being treated for erectile dysfunction finds an association between the use of cholesterol-lowering statins and abnormally low levels of the male hormone testosterone.
The study "sends a signal worthy of observation," said Dr. Irwin Goldstein, director of sexual medicine at Alvarado Hospital in San Diego and editor of the Journal of Sexual Medicine. The report is published in the April issue of the journal.
Goldstein noted that, in his practice, he sees patients "several times a week" who say that their sexual performance declined after they started taking a statin.
But an American epidemiologist who did a similar study said the Italian results could be interpreted as saying that statin use reduces the incidence of erectile dysfunction.
That study, of men in Olmsted County, Minn., found a low incidence of impotence in men taking the drugs, with longer use associated with lower incidence. Men who took statins for nine years were 64 percent less likely to develop erectile dysfunction in that study than those who didn't, said study co-author Jennifer St. Sauver, an epidemiologist at the Mayo Clinic.
The apparently contradictory results could be explained by the different populations in the two studies, St. Sauver said. The Minnesota study included men in the general population, while the Italian study looked only at men being treated for erectile dysfunction.
Thirty percent of the Minnesota men were taking statins. Only 7 percent of the 3,484 men in the Italian study were taking the drugs. The U.S. Centers for Disease Control and Prevention has reported that about 16 percent of U.S. adults use statins. The lower percentage in the Italian study could indicate that statins reduce the need to seek treatment for erectile dysfunction, St. Sauver said.
The Italian study also didn't have a control group of men without sexual problems, she said, so to establish any cause-effect relationship "you would have to take a group of men without erectile dysfunction and see how many are taking statins," St. Sauver said.
Men who take statins and have sexual problems shouldn't stop taking the drug, Goldstein said. "They should see a doctor for a blood test," he said. "If testosterone is low, they should not stop taking statins but should start testosterone treatment."
The Italian study is important because "it is the first to bring up this message in a large number of men," Goldstein added.
One U.S. study, reported in 2007 by the New England Research Institutes, did find lower levels of testosterone in a general population of men taking statins. But detailed analysis of the data found that the reduced levels could be explained by other factors, such as obesity and diabetes, rather than statin use.
That study was done because of reports that statins might lower the risk of prostate cancer by reducing testosterone levels. No such protective effect was found.
Several scattered studies have found a relationship between statin use and lower levels of male hormones. But definitive evidence about such a relationship would require a carefully controlled study, Goldstein said.
Detailed information on statins is given by the U.S. National Library of Medicine.