A Harvard expert shares his Ideas on testosterone-replacement therapy
A meeting with Abraham Morgentaler, M.D.
It might be stated that testosterone is what makes men, men. It gives them their characteristic deep voices, large muscles, and body and facial hair, differentiating them from girls. It stimulates the development of the genitals , plays a role in sperm production, fuels libido, and contributes to normal erections. It also fosters the production of red blood cells, boosts mood, and aids cognition.
Over time, the testicular"machinery" that makes testosterone gradually becomes less effective, and testosterone levels start to fall, by about 1% a year, beginning in the 40s. As men get into their 50s, 60s, and beyond, they may begin to have symptoms and signs of low testosterone like reduced libido and sense of energy, erectile dysfunction, diminished energy, decreased muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" significance low functioning and"gonadism" referring to the testicles). Yet it is an underdiagnosed problem, with only about 5% of those affected receiving treatment.
Much of the current debate focuses on the long-held belief that testosterone may stimulate prostate cancer.
Dr. Abraham Morgentaler, an associate professor of surgery at Harvard Medical School and the director of Men's Health Boston, specializes in treating prostate diseases and male sexual and reproductive difficulties. He has developed specific experience in treating low testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment plans he utilizes his patients, and he thinks experts should reconsider the possible link between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt that the typical man to see a physician?
As a urologist, I have a tendency to see men because they have sexual complaints. The main hallmark of reduced testosterone is low sexual desire or libido, but another can be erectile dysfunction, and some other guy who complains of erectile dysfunction should possess his testosterone level checked. Men may experience other symptoms, like more difficulty achieving an orgasm, less-intense orgasms, a much smaller amount of fluid out of ejaculation, and a sense of numbness in the penis when they see or experience something that would usually be arousing.
The more of the symptoms there are, the more likely it is that a man has low testosterone. Many physicians often discount these"soft symptoms" as a normal part of aging, however, they're often treatable and reversible by decreasing testosterone levels.
Aren't those the very same symptoms that guys have when they're treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are quite a few medications which may reduce libido, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also reduce the quantity of the ejaculatory fluid, no question. However a decrease in orgasm intensity usually doesn't go together with treatment for BPH. Erectile dysfunction does not usually go together with it either, though surely if somebody has less sex drive or less interest, it is more of a struggle to have a good erection.
How can you determine if a person is a candidate for testosterone-replacement treatment?
There are two ways we determine whether somebody has reduced testosterone. One is a blood test and the other is by characteristic signs and symptoms, and the correlation between those two approaches is far from perfect. Normally men with the lowest testosterone have the most symptoms and guys with highest testosterone possess the least. But there are some guys who have low levels of testosterone in their blood and have no signs.
Looking purely at the biochemical numbers, The Endocrine Society* believes low testosterone to be a entire testosterone level of less than 300 ng/dl, and I think that is a sensible guide. But no one really agrees on a number. It is similar to diabetes, where if your fasting sugar is above a certain level, they'll say,"Okay, you've got it." With testosterone, that break point isn't quite as clear.
| *Note: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and shouldn't receive testosterone treatment. For a complete copy of these visit this page guidelines, best site log on to www.endo-society.org. Is total testosterone the right point to be measuring? Or should we be measuring something different? This is another area of confusion and good discussion, but I don't think that it's as confusing as it is apparently in the literature. When most doctors learned about testosterone in medical school, they heard about total testosterone, or all the testosterone in the body. However, about half of the testosterone that is circulating in the blood is not available to cells. It's tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG. The biologically available part of overall testosterone is called free testosterone, and it's readily available to cells. Though it's only a little portion of the total, the free testosterone level is a fairly good indicator of low testosterone. It's not ideal, but the significance is greater than with total testosterone.
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