In medical terms, it’s called late-onset hypogonadism — the gradual decline of the male hormone testosterone beginning in middle age, right around the time men also start gaining weight, losing muscle mass, feeling depressed and suffering from sleep problems, weakness and, most notably, sexual dysfunction.
Whether these changes are directly related to declining hormone levels, however, has long been the subject of sharp debate. Some doctors believe they are, and suggest that any effects of hormone loss (testosterone production slides by about 1% a year in men after age 30) merit testosterone replacement therapy, an increasingly popular but poorly studied treatment that may carry some serious side effects, including an increased risk of prostate cancer, heart attack and stroke, especially in older men.
Other experts regard the treatment of “male menopause,” also called andropause, as the unnecessary medicalization of normal aging. In fact, many middle-aged men with normal hormone levels suffer from low sex drive, depression or fatigue as a result of any number of lifestyle or health factors — job stress, a bad marriage, obesity — that are not directly related to testosterone.
Now, in the first study of its kind, a group of British researchers has sought to determine whether andropause really exists and, if so, what its true symptoms are. The study, published Wednesday in the New England Journal of Medicine, included 3,219 men ages 40 to 79, who were participating in the European Male Aging Study at eight centers in Europe. Using questionnaires, researchers gauged the participants’ general sexual, physical and psychological health. They also measured each man’s blood level of testosterone.
In the final analysis, a cluster of only three symptoms was significantly associated with low testosterone. The study officially defines late-onset hypogonadism as the presence of three sexual symptoms — decreased frequency of morning erection, low sexual desire and erectile dysfunction — along with a total testosterone level of less than 11 nmol per liter. (The participants’ average total testosterone level was about 17 nmol per liter.)
Researchers identified six other symptoms that appeared more frequently as testosterone declined: three physical symptoms (an inability to engage in vigorous activity, such as running, lifting heavy objects or playing strenuous sports; an inability to walk more than 1 km; and an inability to bend, kneel or stoop) and three psychological symptoms (loss of energy, sadness and fatigue). But they were only weakly associated with testosterone, and overall, the researchers found, individual symptoms of andropause appeared frequently in men who didn’t have it.
“Even with the nine rigorously selected symptoms, differences in mean testosterone levels between symptomatic men and asymptomatic men were minimal, reflecting the weak overall association between symptoms and testosterone levels in this population,” the authors write.
The researchers also found that just 2% of study participants qualified for a diagnosis of late-onset hypogonadism, with the chances of diagnosis increasing with age: 0.1% at age 40-49, 0.6% at age 50-59, 3.2% at age 60-69, and 5.1% at age 70-79. The findings could be taken to suggest that the millions of men currently receiving testosterone replacement therapy for symptoms of andropause are being treated unnecessarily.
“The documentation of low testosterone levels in symptomatic elderly men does not invariably imply that a low testosterone level is the only or foremost cause of their symptoms,” the authors write. It’s entirely likely, in other words, that a bad sex life won’t be cured with a testosterone patch.