For women of a certain age, menopause is a fact of life. But this middle-age change no longer looks so feminine.
More men are arriving in doctors' offices complaining of sexual dysfunction, weight gain, fatigue, depression and other unpleasant, but potentially vague, symptoms. In some of these men, a blood test reveals low testosterone levels. And there has been a corresponding uptick in testosterone prescriptions, one approach to treating low male hormone levels.
For these patients, doctors like Robert Brannigan in Chicago may give testosterone replacement a trial run to treat symptoms which, he said, can have a profound effect on a patient.
"It helps many, many of these individuals to have overall improved quality of life. It not only affects them, but very often their partners and their intimate relationships," said Brannigan, an attending physician at Northwestern Memorial Hospital and an associate professor of urology at the Northwestern University Feinberg School of Medicine.
Male menopause, as it has been dubbed, is controversial. First there's the name, which experts dislike because it draws an inaccurate parallel with the female experience. (The accurate term for men is late-onset hygonadism.) What's more, the disorder itself is not universally accepted, with some saying there is weak evidence for a link between symptoms and decreased hormone levels, and questioning whether benefits outweigh the risk and unknowns of testosterone prescriptions.
"I think the question that arises is how much of this is related to hormones and how much of it is the facts of life that we experience as we age," said Dr. Thomas Walsh, an assistant professor and director of male reproductive and sexual medicine at the University of Washington's School of Medicine in Seattle. Walsh, a urologist, prescribes testosterone after what he describes as "heavy informed consent." [7 Ways the Mind and Body Change With Age]
"There is still a lot of controversy, and I don't think we have all the answers yet. You have to take the data at hand and apply it to the individual," he said.
Up to 4 million men may have low testosterone, with most caused by age-related declines. However, only a minority receive treatment, according to Walsh. That number of men affected is expected to rise.
The female misnomer
'Male menopause' may grab attention, but experts dislike the term, because it glosses over the significant differences between the hormonal changes men and women experience as they age.
"Nobody doubts female menopause, and nobody doubts the mechanism by which it happens, that's not the case for male menopause," said Dr. Ike Iheanacho, editor of the journal Drug and Therapeutics Bulletin, which in June published a review on using testosterone to treat so-called male menopause. "That epithet is unhelpful, because it deters people from doing what we [have] done, which is look at the evidence."
The review, which reflected the journal's opinion, found weak causal evidence that age-related hormone declines cause symptoms in men, a lack of long-term data, and at best, mixed results for short-term treatment.
For a woman, menopause marks the end of fertility and occurs when progesterone and estrogen, produced by the ovaries, drop off. Symptoms can last several years, according to the U.S. National Institutes of Health (NIH). Hormonal changes in men are quite different. Testosterone levels can decrease by about 1 percent to 2 percent each year after about the age of 40. While menopause is a universal experience for women, testosterone does not decline in all men. Other factors besides aging, like obesity or injury, are associated with low testosterone.
For many years, long-term hormone replacement for women was considered protective for all kinds of ailments, until study results in 2002 revealed it increased risks of heart disease, stroke, blood clots and breast cancer, according to the NIH.
This history has implications for men with low hormones and symptoms, Walsh said. "You are seeing today far more caution on the part of clinicians and investigators."
Two papers published in the July issue of the New England Journal of Medicine addressed the diagnosis of hypogonadism and its treatment.
In one study, researchers led by Frederick Wu of the University of Manchester used data from 3,369 European men to find correlations between testosterone levels and a battery of potential symptoms. As a result, they suggested that the presence of at least three measures of sexual dysfunction, including frequency of thoughts about sex and erectile function, in a man with a testosterone level below 11 nanomoles per liter could be used to define late-onset hypogonadism. (The study defined a decreased level as between 13 and 8 nanomoles per liter for total testosterone.) However, these symptoms were also widely reported by men who did not suffer from depressed hormone levels.
This causal relationship between hormone levels and symptoms is always a question, according to Dr. William Bremner, chairman of the department of medicine at the University of Washington's School of Medicine, who wrote about that research in an editorial in the journal.
"In truth you don't know that those are due to the testosterone until you give men testosterone and see whether those symptoms are improved," he said.
Testosterone has been shown to increase muscle mass and strength, so a second study in the same journal issue set out to test how much testosterone supplementation was needed to increase mobility among men ages 65 or older with difficulty walking or climbing stairs. The authors, led by Shehzad Basaria of Boston University's School of Medicine and Boston Medical Center, found evidence that testosterone did improve the men's strength. However, the men taking testosterone also experienced an unusually high rate of cardiovascular problems.
The latter result is surprising, and may be due to chance, since previous studies have not shown a connection between testosterone and cardiovascular risk, Bremner said.
The Women's Health Initiative Study, which revealed risks of hormone replacement therapy, followed a total of 161,808 women over 15 years. No long-term research like this has been conducted in men, but it is needed, Bremner said.
"There really are a large number of older men receiving testosterone and the numbers seem to be increasing and it's not something that is going away," he added.
On the rise
In roughly the past four years, Brannigan's urology practice has seen an increase in patients he said are suffering from late-onset hypogonadism.
"Certainly, there is no question we are seeing more patients, and the question is, and I don't think we know, is it due to increased public awareness or is it due to increased prevalence," Brannigan said. Still, he estimates that 95 percent of cases are undiagnosed.
His office is not unique. With an aging, more at-risk population living in a post-Viagra era, when taboos on men's sexual health issues like erectile dysfunction are lifting, the increase is expected to continue. Prescriptions appear headed up as well.
Between 2005 and 2009, testosterone prescriptions dispensed by pharmacies rose 65 percent in the United States, according to a LiveScience analysis of data from IMS Health, a heath-care information and consulting company.
There is also a lifestyle connection. Low testosterone is associated with obesity, diabetes and metabolic syndrome — a combination of disorders linked to diabetes and cardiovascular disease. All three are on the rise within the United States, according to data from the Centers for Disease Control and Prevention.