A Harvard Specialist 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 at puberty, plays a role in sperm production, fuels libido, and leads to regular erections. It also fosters the creation of red blood cells, boosts mood, and aids cognition.
Over time, the "machinery" which produces testosterone gradually becomes less powerful, and testosterone levels begin to fall, by approximately 1 percent a year, starting in the 40s. As guys get into their 50s, 60s, and beyond, they might begin to have signs and symptoms of low testosterone like reduced sex drive and sense of energy, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often called hypogonadism ("hypo" significance low functioning and"gonadism" speaking to the testicles). Yet it is an underdiagnosed issue, with only about 5 percent of those affected undergoing therapy.
Various studies have shown that testosterone-replacement therapy can offer a vast range of benefits for men with hypogonadism, including enhanced libido, mood, cognition, muscle mass, bone density, and red blood cell production. But little consensus exists on what constitutes low testosterone, when testosterone supplementation makes sense, or what dangers patients face. Much of the current debate focuses on the long-held belief that testosterone can stimulate prostate cancer.
He has developed specific 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 connection between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt the typical man to see a physician?
As a urologist, I tend to observe men because they have sexual complaints. The main hallmark of low testosterone is reduced sexual libido or desire, but another may be erectile dysfunction, and any guy who complains of erectile dysfunction must get his testosterone level checked. Men can experience different symptoms, such as more trouble achieving an orgasm, less-intense climaxes, a lesser quantity of fluid from ejaculation, and a sense of numbness in the penis when they see or experience something which would usually be arousing.
The more of these symptoms there are, the more probable it is that a man has low testosterone. Many physicians tend to dismiss those"soft symptoms" as a normal part of aging, however, they are often treatable and reversible by normalizing testosterone levels.
Are not those the same symptoms that men have when they are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are a number of medications which may lessen sex drive, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the amount of the ejaculatory fluid, no wonder. However a reduction in orgasm intensity usually doesn't go together with treatment for BPH. Erectile dysfunction does not usually go together with it , though certainly if a person has less sex drive or less attention, it is more of a challenge to get a good erection.
How can you decide if or not a man is a candidate for testosterone-replacement therapy?
There are just two ways we determine whether somebody has reduced 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 perfect. Generally guys with the lowest testosterone have the most symptoms and guys with maximum testosterone possess the least. But there are some men who have reduced levels of testosterone in their blood and have no signs.
Looking at the biochemical numbers, The Endocrine Society* considers low testosterone to be a total testosterone level of less than 300 ng/dl, and I believe that is a sensible guide. However, no one really agrees on a number. It's not like diabetes, where if your fasting glucose is over a certain level, they will say,"Okay, you've got it." With testosterone, that break point isn't quite as apparent.
| *Note: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and shouldn't receive testosterone therapy. |
Is total testosterone the right thing to be measuring? Or should we be measuring something else?
Well, this is another area of confusion and great debate, but I don't think it's as confusing as it appears to be in the literature. When most doctors learned about testosterone in medical school, they learned about total testosterone, or all of the testosterone in the human body. However, about half of their testosterone that is circulating in the blood is not readily available to cells. It's tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG.
The available part of overall testosterone is known as free testosterone, and it is readily available to the cells. Even though it's just a little portion of the total, the free testosterone level is a pretty good indicator of reduced testosterone. It is not perfect, but the correlation is greater than with testosterone.
Endocrine Society recommendations outlinedThis professional organization urges testosterone treatment for men who have Therapy Isn't recommended for men who have
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What kinds of testosterone-replacement treatment are available? *
The earliest form is the injection, which we use since it's cheap and since we reliably get fantastic testosterone levels in nearly everybody. The disadvantage is that a person should come in every few weeks to find a shot. A roller-coaster effect may also occur as blood glucose levels peak and return to research. [Watch"Exogenous vs. endogenous testosterone," above.]
Topical therapies help maintain a more uniform amount of blood glucose. The first kind of topical therapy has been a patch, but it has a quite high rate of skin irritation. In one study, as many as 40 percent of people that used the patch developed a red area on their skin. That restricts its usage.
The most commonly used testosterone preparation in the United States -- and also the one I begin almost everyone off with -- is a topical gel. The gel comes from miniature tubes or in a unique dispenser, and you rub it on your shoulders or upper arms once a day. Based on my experience, it tends to be consumed to great levels in about 80% to 85% of guys, but leaves a significant number who do not consume enough for it to have a positive impact. [For details on several different formulations, see table below.]
Are there any drawbacks to using gels? How much time does it require them to get the job done?
Men who begin using the implants need to return in to have their own testosterone levels measured again to be certain they're absorbing the proper amount. Our target is the mid to upper assortment of normal, which generally means approximately 500 to 600 ng/dl. The concentration of testosterone in blood actually goes up quite quickly, within a few doses. I usually measure it after two weeks, though symptoms may not alter for a month or two.