A Harvard Specialist shares his thoughts on testosterone-replacement Treatment
A meeting with Abraham Morgentaler, M.D.
It could be stated that testosterone is what makes guys, 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 , plays a role in sperm production, fuels libido, and leads to normal erections. Additionally, it 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, 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). Researchers estimate that the condition affects anywhere from two to six million men in the United States. Yet it's an underdiagnosed issue, with only about 5% of those affected undergoing therapy.
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 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 problems. 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 best site diagnosisWhat symptoms and signs of low testosterone prompt that the average man to see a doctor?
As a urologist, I tend to see men because they have sexual complaints. The primary hallmark of reduced testosterone is reduced 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 can experience different symptoms, like more trouble achieving an orgasm, less-intense climaxes, a much lesser quantity of fluid out of 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 often discount 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 are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are quite a few medications which may reduce libido, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the quantity of the ejaculatory fluid, no wonder. However a decrease in orgasm intensity usually does not go along with therapy for BPH. Erectile dysfunction does not ordinarily go together 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 if 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 men with the lowest testosterone have the most symptoms and men with maximum testosterone possess the least. But there are some guys who have low levels of testosterone in their blood and have no symptoms.
Looking at the biochemical numbers, The Endocrine Society* believes low testosterone for a total testosterone level of less than 300 ng/dl, and I believe that is 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 isn't quite as clear.
| *Note: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and should not receive testosterone therapy. |
Is complete testosterone the right point to be measuring? Or if we are measuring something else?
This is just another area of confusion and great discussion, but I don't think that it's as confusing as it appears to be 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 their testosterone that's circulating in the blood is not readily available to the cells. It's closely bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG.
The available portion of overall testosterone is called free testosterone, and it is readily available to the cells. Though it's only a little fraction of this total, the free testosterone level is a fairly good indicator of low testosterone. It is not ideal, but the correlation is greater compared to total testosterone.
Endocrine Society recommendations summarizedThis professional organization urges testosterone therapy for men who have both 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 since levels start to drop after 10 or even 11 a.m.. But the data behind this recommendation were drawn from healthy young men. Two recent studies showed little change in blood glucose levels in men 40 and older over the course of this day. One reported no change in typical testosterone till after 2 p.m. Between 6 and 2 p.m., it went down by 13 percent, a modest amount, and probably insufficient to affect diagnosis. Most guidelines still say it's important to do the evaluation in the morning, however for men 40 and above, it probably doesn't matter much, provided that they obtain their blood drawn before 5 or 6 p.m.
There are some very interesting findings about dietary supplements. By way of example, it appears that individuals that have a diet low in protein have lower testosterone levels than males who eat more protein. But diet hasn't been studied thoroughly enough to make any recommendations that are clear.
Exogenous vs. endogenous testosteroneWithin the following guide, testosterone-replacement treatment refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that is manufactured outside the body. Based upon the formula, therapy can lead to skin irritation, breast enlargement and tenderness, sleep apnea, acne, reduced sperm count, increased red blood cell count, and other side effects. In a recent prospective study, 36 hypogonadal men took a daily dose of clomiphene citrate for three or more months. Within four to six weeks, all of 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 formulas. But unlike adrenal gland, clomiphene citrate maintains -- and potentially enriches -- sperm production. This makes medication like clomiphene citrate one of only a few choices for men with low testosterone who wish to father children. What kinds of testosterone-replacement therapy are available? * The oldest form is an injection, which we use since it's inexpensive and because we faithfully become fantastic testosterone levels in nearly everybody. The disadvantage is that a man should come in every couple of weeks to find a shot. A roller-coaster effect can also occur as blood testosterone levels peak and return to baseline. Topical therapies help preserve a more uniform amount 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 red area in their skin. That restricts its use. The most commonly used testosterone preparation from the United States -- and also the one I start almost everyone off with -- is a topical gel. There are just two brands: AndroGel and Testim. According to my experience, it tends to be absorbed to great degrees in about 80% to 85% of guys, but leaves a substantial number who do not absorb enough for this to have a positive effect. [For details on various formulations, see table below.] Are there any downsides to using gels? How long does it require them to work? Men who begin using the gels have to come back in to have their own testosterone levels measured again to make certain they are absorbing the right quantity. Our target is that the mid to upper range of normal, which usually means approximately 500 to 600 ng/dl. The concentration of testosterone in the blood really goes up quite fast, in just several doses. I normally measure it after two weeks, even though symptoms may not alter for a month or two. |