Men in US and UK undergo testosterone therapy without clear medical need, study finds

Jan. 30, 2014

If the warnings on the Viagra commercials haven’t given you pause (who would wait four hours before calling a doctor?), maybe you wouldn’t be deterred by ads for a new testosterone supplement. The high-speed voice-over on the supplement ad warns about prostate and breast cancers in men and the danger of one’s wife and daughter growing body hair and developing breast cancer if they mistake the stuff in the medicine cabinet for an antiperspirant.

Dr. Bradley Layton

Dr. Bradley Layton

Now, researchers, led by J. Bradley Layton, PhD, and others at The University of North Carolina at Chapel Hill’s Gillings School of Global Public Health, have undertaken a study of men in the United States and United Kingdom who seek testing and initiate testosterone supplementation.

Their study’s aim was to describe the scope of testing and treatment for low testosterone levels, and their findings lead them to encourage physicians and other prescribers to consider carefully the medical necessity of the supplement, especially given widening use and persistent concerns about these products’ safety and efficacy.

The research, published in the Endocrine Society’s Journal of Clinical Endocrinology and Metabolism, found that although testosterone use has increased sharply among older men in the past decade, many patients appear to have normal testosterone levels and do not meet clinical guidelines for treatment.

Testosterone is a key male sex hormone involved in maintaining sex drive, sperm production and bone health. Since testosterone levels tend to decline naturally as men age, lower levels of the hormone do not necessarily mean that an individual has hypogonadism, a condition that results from low testosterone. As the population ages and an increasing number of men struggle with obesity and diabetes, more men may experience low testosterone levels without meeting diagnostic criteria or displaying symptoms of hypogonadism.

“Over the past decade, older and middle-aged men are increasingly being tested for low testosterone levels and are being prescribed testosterone medications, particularly in the U.S.,” said Layton, a postdoctoral fellow in epidemiology at the Gillings School.

“While direct-to-consumer advertising and the availability of convenient topical gels may be driving more men to seek treatment, our study suggests that many of those who start taking testosterone may not have a clear medical indication to do so,” he said.

To study testosterone trends, the retrospective incident-user cohort study analyzed commercial and Medicare insurance claims from the U.S. and general practitioner health-care records from the U.K. during the period between 2000 and 2011. The study identified 410,019 American men and 6,858 U.K. men who began taking testosterone during this period. The analysis also found more than 1.1 million U.S. men and 66,000 U.K. men who had their testosterone levels tested during this time.

Since 2000, the number of men beginning testosterone therapy has almost quadrupled in the U.S. while only increasing by a third in the U.K. The majority of these patients had not had their testosterone levels measured recently or only had them tested once prior to beginning treatment.

The Endocrine Society’s clinical practice guidelines on testosterone therapy in adult men recommends making a clinical diagnosis of androgen deficiency, or low testosterone, only in men with consistent symptoms and unequivocally low testosterone levels.

While testosterone testing has increased substantially in both countries, the study found the testing appeared to be more targeted in the U.K. Many of the tests there identified men who did have reduced levels of the hormone.

“In the United States, we saw a clear trend where more and more men being tested actually had normal testosterone levels and non-specific symptoms,” Layton said. “This is cause for concern as research examines potential risks associated with testosterone use.”

Other UNC co-authors of the study include Til Stürmer, MD, professor of epidemiology and director of the UNC Center for Pharmacoepidemology; M. Alan Brookhart, PhD, associate professor of epidemiology; and Dongmei Li, epidemiologist, all at the Gillings School; and Julie Sharpless, MD, assistant professor of medicine and director of the Multidisciplinary Pituitary Adenoma Clinic in the School of Medicine.

Other co-authors include Susan Jick, PhD, professor of epidemiology at Boston University; and Dr. Christoph R. Meier, epidemiology professor in the Division of Clinical Pharmacology and Toxicology at the University of Basel in Basel, Switzerland.

The study, funded by the National Institute of Health’s National Institute on Aging, is available online ahead of print.


Gillings School of Global Public Health contact: David Pesci, director of communications, (919) 962-2600 or dpesci@unc.edu.