A Harvard expert shares his thoughts on testosterone-replacement therapy
An interview with Abraham Morgentaler, M.D.
It could be said that testosterone is the thing that makes guys, men. It gives them their characteristic deep voices, large muscles, and facial and body hair, differentiating them from girls. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and contributes to regular erections. Additionally, it fosters the creation of red blood cells, boosts mood, and assists cognition.
Over time, the "machinery" which makes testosterone gradually becomes less powerful, and testosterone levels start to fall, by approximately 1% per year, starting in the 40s. As men get in their 50s, 60s, and beyond, they may start to have symptoms and signs of low testosterone such as lower libido and sense of vitality, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and anemia. Taken together, these symptoms and signs are often called hypogonadism ("hypo" significance low functioning and"gonadism" referring to the testicles). Researchers estimate that the illness affects anywhere from two to six million men in the United States. Yet it's an underdiagnosed problem, with only about 5 percent of those affected undergoing therapy.
Studies have revealed that testosterone-replacement therapy may provide a wide selection of benefits for men with hypogonadism, such as enhanced libido, mood, cognition, muscle mass, bone density, and red blood cell production. Much of the current debate focuses on the long-held belief that testosterone can 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 reproductive and sexual difficulties. He's developed particular experience in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment strategies he utilizes his own patients, and he thinks experts should reconsider the potential link between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt that the average man to find a doctor?
As a urologist, I have a tendency to see guys because they have sexual complaints. The primary hallmark of reduced testosterone is low sexual libido or desire, but another may be erectile dysfunction, and any guy who complains of erectile dysfunction should get his testosterone level checked. Men can experience other symptoms, such as more trouble achieving an orgasm, less-intense orgasms, a lesser amount of fluid from ejaculation, and a sense of numbness in the manhood when they see or experience something that would usually be arousing.
The more of these symptoms you will find, the more likely it is that a man has low testosterone. Many physicians tend to discount those"soft symptoms" as a normal part of aging, but they're often treatable and reversible by normalizing 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 drugs that may reduce libido, such as the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the amount of the ejaculatory fluid, no question. However a reduction in orgasm intensity normally doesn't go along with treatment for BPH. Erectile dysfunction does not ordinarily go together with it either, though certainly if a person has less sex drive or less attention, it's more of a challenge to get a good erection.
How can you decide whether a man is a candidate for testosterone-replacement treatment?
There are just two ways that we determine whether somebody has low testosterone. One is a blood test and the other one is by characteristic signs and symptoms, and the correlation between those two methods is far from ideal. Normally guys with the lowest testosterone have the most symptoms and men with highest testosterone possess the least. However, there are a number of guys who have low levels of testosterone in their blood and have no symptoms.
Looking purely at the biochemical amounts, The Endocrine Society* believes low testosterone for a entire testosterone level of less than 300 ng/dl, and I think that's a reasonable guide. But no one quite agrees on a number. It is similar to diabetes, in which if your fasting sugar is over a certain level, they will say,"Okay, you've got it." With testosterone, that break point isn't quite as apparent.
| *Notice: The Endocrine Society publishes clinical practice guidelines with recommendations for click this link who More Bonuses should and shouldn't receive testosterone therapy. Is total testosterone the right thing to be measuring? Or should we be measuring something else? This is just another area of confusion and good discussion, but I do not think that it's as confusing as it is apparently from the literature. When most physicians learned about testosterone in medical school, they heard about overall testosterone, or all of the testosterone in the body. But about half of the testosterone that's circulating in the bloodstream is not available to cells. It's tightly bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG. The biologically available part of total testosterone is called free testosterone, and it's readily available to cells. Even though it's only a little portion of this overall, the free testosterone level is a fairly good indicator of reduced testosterone. It's not perfect, but the correlation is greater than with total testosterone.
What kinds of testosterone-replacement treatment are available? * The oldest form is the injection, which we still use because it is cheap and because we reliably become good testosterone levels in nearly everybody. The drawback is that a man needs to come in every few weeks to find a shot. A roller-coaster effect may also happen as blood testosterone levels peak and then return to baseline. [Watch"Exogenous vs. endogenous testosterone," above.] Topical treatments help preserve a more uniform amount of blood glucose. The first form of topical therapy was a patch, but it has a very high rate of skin irritation. In one study, as many as 40 percent of people that used the patch developed a reddish area in their skin. That restricts its usage. The most widely used testosterone preparation from the United States -- and the one I start almost everyone off with -- is a topical gel. The gel comes in tiny tubes or within a unique dispenser, and you rub it on your shoulders or upper arms once a day. According to my experience, it has a tendency to be consumed to great degrees in about 80% to 85 percent of guys, but leaves a significant number who do not consume sufficient for this to have a favorable effect. [For details on several different formulations, see table ] Are there any drawbacks to using gels? How long does it take for them to work? Men who start using the gels have to come back in to have their testosterone levels measured again to make sure they are absorbing the proper quantity. Our goal is that the mid to upper assortment of normal, which generally means approximately 500 to 600 ng/dl. The concentration of testosterone in the blood actually goes up quite quickly, within a few doses. I usually measure it after 2 weeks, even although symptoms may not change for a month or two. |