A Harvard Specialist shares his thoughts on testosterone-replacement Treatment
An interview 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 fosters the production of red blood cells, boosts mood, and assists cognition.
Over time, the "machinery" that produces testosterone gradually becomes less effective, and testosterone levels begin to fall, by about 1 percent a year, beginning in the 40s. As guys get into their 50s, 60s, and beyond, they may begin to have signs and symptoms of low testosterone such as reduced sex drive and sense of vitality, erectile dysfunction, diminished energy, decreased muscle mass and bone density, and anemia. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" meaning low functioning and"gonadism" speaking to the testicles). Yet it's an underdiagnosed issue, with only about 5% of these affected undergoing therapy.
But little consensus exists on what constitutes low testosterone, when testosterone supplementation makes sense, or what risks patients face.
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 problems. He's developed particular expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment strategies he uses with his own patients, and why he believes specialists should rethink the possible link between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt that the typical person to find a physician?
As a urologist, I have a tendency to see men because they have sexual complaints. The primary hallmark of low testosterone is low sexual libido or desire, but another may be erectile dysfunction, and some other guy who complains of erectile dysfunction must possess his testosterone level checked. Men may experience other symptoms, such as more difficulty achieving an orgasm, less-intense orgasms, a smaller amount of fluid from ejaculation, and a sense of numbness in the manhood when they see or experience something which would usually be arousing.
The more of the symptoms you will find, the more probable it is that a man has low testosterone. Many physicians tend to dismiss these"soft symptoms" as a normal part of aging, but they are 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 a number of drugs that 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 question. But a reduction in orgasm intensity usually does not go along with treatment for BPH. Erectile dysfunction does not usually go along with it either, though certainly if a person has less sex drive or less attention, it is more of a struggle to have a fantastic erection.
How do you determine whether a man is a candidate for testosterone-replacement therapy?
There are two ways that we determine whether someone 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 guys who have reduced levels of testosterone in their blood and have no signs.
Looking purely at the biochemical numbers, The Endocrine Society* considers low testosterone for a entire testosterone level of less than 300 ng/dl, and I think that's a sensible guide. However, no one really agrees on a number. It's not like diabetes, in which 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 publishes clinical practice guidelines with recommendations for who should and should not receive testosterone treatment. For a complete why not try these out copy of the guidelines, log on to www.endo-society.org. |
Is complete testosterone the right point to be measuring? Or if we are measuring something else?
This is just another area of confusion and good debate, but I do not think it's as confusing as it appears to be from the literature. When most doctors learned about testosterone in medical school, they heard about overall testosterone, or all the testosterone in the human body. But about half of their testosterone that is circulating in the bloodstream isn't readily available to the cells. It is closely bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG.
The available part of overall testosterone is called free testosterone, and it is readily available to the cells. Though it's only a little portion of this total, the free testosterone level is a fairly good indicator of low testosterone. It is not perfect, but the significance is greater than with testosterone.
Endocrine Society recommendations summarizedThis professional organization urges testosterone therapy for men who have Therapy is not Suggested for men who have
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Do time daily, diet, or other factors influence testosterone levels?
For many years, the recommendation has been to receive a testosterone value early in the morning because levels start to fall after 10 or 11 a.m.. However, the information behind that recommendation were attracted to healthy young men. Two recent studies demonstrated little change in blood testosterone levels in men 40 and mature within the course of the day. One reported no change in average testosterone till after 2 p.m. Between 6 and 2 p.m., it went down by 13 percent, a modest sum, and probably not enough to influence identification. Most guidelines nevertheless say it's important to perform the evaluation in the morning, but for men 40 and above, it likely does not matter much, as long as they obtain their blood drawn before 6 or 5 p.m.
There are some very interesting findings about dietary supplements. By way of example, it appears that those that have a diet low in protein have lower testosterone levels than males who consume more protein. But diet hasn't been studied thoroughly enough to create any recommendations that are clear.
In the following guide, testosterone-replacement treatment refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that is produced outside the body. Based upon the formula, therapy can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, reduced sperm count, increased red blood cell count, along with additional side effects.
Preliminary studies have proven that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, can foster the production of natural testosterone, termed endogenous testosterone, in men. Within four to six months, each one the men had heightened levels of testosterone; none reported any side effects during the year they were followed.
Because clomiphene citrate is not approved by the FDA for use in men, little information exists about the long-term effects of taking it (including the risk of developing prostate cancer) or whether it is more effective at boosting testosterone than exogenous formulations. But unlike exogenous testosterone, clomiphene citrate preserves -- and potentially enriches -- sperm production. This makes medication such as clomiphene citrate one of just a few choices for men with low testosterone who want to father children.
FormulationsWhat forms of testosterone-replacement therapy are available? *
The earliest form is the injection, which we use because it's inexpensive and because we reliably become fantastic testosterone levels in almost 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 glucose levels peak and then return to baseline. [See"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 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 the one I begin almost everyone off -- is a topical gel. Based on my experience, it tends to be consumed to great levels in about 80% to 85% of guys, but that leaves a substantial number who do not consume enough for this to have a favorable effect. [For details on several different formulations, see table below.]
Are there any downsides to using dyes? How long does it require them to get the job done?
Men who start using the implants need to come back in to have their testosterone levels measured again to be sure they're absorbing the proper amount. Our goal is the mid to upper range of normal, which generally means around 500 to 600 ng/dl. The concentration of testosterone in blood actually goes up quite fast, within several doses. I normally measure it after two weeks, even though symptoms may not alter for a month or two.