''Current statin therapy is associated with a twofold increased prevalence of hypogonadism," a condition in which men don't produce enough testosterone, study author Giovanni Corona, MD, PHD, a researcher at the University of Florence in Italy.
Although previous studies have produced mixed findings on the possible link between taking cholesterol-lowering drugs like statins and a drop in testosterone, most studies involved a limited number of patients, with few studies including more than 50 people, Corona says.
"Our study is the first report showing a negative association between statin therapy and testosterone levels in a large series of patients consulting for sexual dysfunction," says Corona.
Statin Therapy Rising
About one of six adults in the U.S. has high cholesterol, according to the CDC. The number of people buying a statin (such as Lipitor or Zocor) rose 88% from 2000 to 2005, from 15.8 million people to 29.7 million, according to the federal Agency for Healthcare Research and Quality.
Statins, Testosterone, and ED: The Study
Corona and colleagues evaluated 3,484 men, average age 51, who visited an outpatient clinic at the University of Florence with complaints of sexual dysfunction between January 2002 and August 2009.
Of that total, 244, or 7%, were being treated with statins for their high cholesterol. Most often the statin was simvastin (Zocor) or atorvastatin (Lipitor).
The researchers calculated the men's total testosterone as well as free testosterone, the amount of unbound testosterone in the bloodstream.
When they compared men on statins to those not, the men on statins were twice as likely to have low testosterone, regardless of which of three commonly used thresholds for low testosterone they looked at.
The researchers emphasize they have found a link, not a cause and effect, between statins and lower testosterone levels. However, the researcher can't explain the link with certainty.
One possibility is that low testosterone levels and the need for statin treatment share some common causes, according to Corona
Some researchers also have looked at the possibility that the statins' inhibition of cholesterol synthesis may interfere with the production of testosterone, which depends on a supply of cholesterol. The statins may disrupt the pituitary feedback to the testicles, telling them to produce testosterone.
Statins, Testosterone, and ED: Other Views
''This is huge," says Irwin Goldstein, MD, director of sexual medicine at Alvarado Hospital in San Diego and editor-in-chief of the Journal of Sexual Medicine.
The study results, he says, demonstrate the need for more study to replicate the link between statins and lower testosterone levels and figure out the reason for the link.
For consumers, he says, the message is for men on statins to pay attention to early warning signs of testosterone deficiency. That includes falling asleep after meals when they did not in the past, noticing poorer athletic performance, having a change from an upbeat mood to a grumpy mood, and experiencing a reduced sex drive, Goldstein says.
If a man suspects testosterone deficiency, Goldstein says he should ask his doctor about checking his testosterone levels.
- Corona, G. Journal of Sexual Medicine, April 2010.
- Giovanni Corona, MD, PhD, researcher, andrology and sexual medicine unit, University of Florence, Florence, Italy, and endocrinology unit, Maggiore Hospital, Bologna, Italy.
- Irwin Goldstein, MD, director of sexual medicine, Alvarado Hospital, San Diego; editor-in-chief, Journal of Sexual Medicine.