A Harvard expert shares his thoughts on testosterone-replacement Treatment
A meeting with Abraham Morgentaler, M.D.
It might be said that testosterone is the thing that makes men, guys. It gives them their characteristic deep voices, large muscles, and body and facial hair, distinguishing them from girls. It stimulates the growth of the genitals at puberty, plays a role in sperm production, fuels libido, and leads to normal erections. Additionally, it boosts the production of red blood cells, boosts mood, and assists cognition.
Over time, the testicular"machinery" which makes testosterone slowly becomes less powerful, and testosterone levels start to drop, by approximately 1% per year, starting in the 40s. As men get into their 50s, 60s, and beyond, they might start to have symptoms and signs of low testosterone like lower sex drive and sense of energy, erectile dysfunction, decreased energy, reduced muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often called hypogonadism ("hypo" meaning low working and"gonadism" referring to the testicles). Researchers estimate that the condition affects anywhere from two to six million men in the USA. Yet it is an underdiagnosed problem, with just about 5 percent of these 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 reproductive and sexual difficulties. He has developed particular expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he utilizes his patients, and he thinks experts should reconsider the potential connection between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt the average man to see a doctor?
As a urologist, I tend to see men since they have sexual complaints. The main hallmark of reduced testosterone is reduced sexual desire or libido, but another can be erectile dysfunction, and any man who complains of erectile dysfunction should get his testosterone level checked. Men may experience other symptoms, such as more difficulty achieving an orgasm, less-intense orgasms, a smaller amount of fluid out of ejaculation, and a feeling of numbness in the penis when they see or experience something that would normally be arousing.
The more of these symptoms you will find, the more probable it is that a man has low testosterone. Many physicians often discount those"soft symptoms" as a normal part of aging, however, they're often treatable and reversible by normalizing testosterone levels.
Aren't those the same symptoms that men have when they're treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are quite a few medications which may lessen sex drive, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the quantity of the ejaculatory fluid, no question. But a reduction in orgasm intensity usually doesn't go together with treatment for BPH. Erectile dysfunction does not usually go along with it , though certainly if somebody has less sex drive or less attention, it is 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 we determine whether someone has reduced testosterone. One is a blood test and the other is by characteristic symptoms and signs, and the correlation between these two approaches is far from perfect. Generally guys with the lowest testosterone have the most symptoms and guys with highest testosterone have the least. However, there are some men who have reduced levels of testosterone in their blood and have no signs.
Looking purely at the biochemical amounts, The Endocrine Society* believes low testosterone to be a total testosterone level of less than 300 ng/dl, and I believe that's a reasonable guide. However, no one quite agrees on a number. It is not like diabetes, where if your fasting sugar is over a certain level, they'll say,"Okay, you've got it." With testosterone, that break point is not quite as apparent.
*Note: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and should not receive testosterone therapy. For a complete copy of these guidelines, log useful link on to www.endo-society.org. |
Is complete testosterone the right point to be measuring? Or should we be measuring something else?
This is another area of confusion and great discussion, but I do not think it's as confusing as it is apparently in the literature. When most physicians learned about testosterone in medical school, they learned about overall testosterone, or all the testosterone in the human body. But about half of the testosterone that is circulating in the bloodstream isn't available to cells. It is tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG.
The biologically available portion of total testosterone is called free testosterone, and it is readily available to the cells. Though it's only a little fraction of this overall, the free testosterone level is a pretty good indicator of reduced testosterone. It's not ideal, but the correlation is greater compared to total testosterone.
Endocrine Society recommendations outlinedThis professional organization recommends testosterone treatment for men who have both Therapy is not recommended for men who have
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What forms of testosterone-replacement therapy are available? *
The earliest form is the injection, which we use because it's cheap and since we faithfully get good testosterone levels in nearly everybody. The disadvantage is that a person should come in every couple of weeks to find a shot. A roller-coaster effect may also happen as blood testosterone levels peak and then return to research. [Watch"Exogenous vs. endogenous testosterone," above.]
Topical treatments help preserve a more uniform level of blood testosterone. The first form of topical treatment has been 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 on their skin. That limits its usage.
The most widely used testosterone preparation from the United States -- and the one I start almost everyone off -- is a topical gel. The gel comes in tiny tubes or within a special dispenser, and you rub it on your shoulders or upper arms once a day. According to my experience, it has a tendency to be absorbed to good levels in about 80% to 85 percent of men, but that leaves a significant number who do not consume enough for this to have a favorable effect. [For specifics on several different formulations, see table below.]
Are there any drawbacks to using dyes? How much time does it take for them to work?
Men who begin using the gels have to come back in to have their own testosterone levels measured again to be sure they are absorbing the right amount. Our goal is the mid to upper assortment of normal, which generally means around 500 to 600 ng/dl. The concentration of testosterone in blood really goes up quite quickly, in just several doses. I usually measure it after 2 weeks, even though symptoms may not alter for a month or two.