A Harvard expert shares his Ideas on testosterone-replacement Treatment
A meeting 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 boosts 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 men get into their 50s, 60s, and beyond, they might start to have signs and symptoms of low testosterone like lower 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" 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 issue, with only about 5% 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'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 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 person to find a doctor?
As a urologist, I tend to observe men since they have sexual complaints. The primary hallmark of reduced testosterone is low sexual libido or desire, but another may be erectile dysfunction, and any man who complains of erectile dysfunction must get his testosterone level checked. Men may experience different symptoms, like more difficulty achieving an orgasm, less-intense climaxes, a much smaller amount of fluid out of 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 often dismiss these"soft symptoms" as a normal part of aging, however, they are often treatable and reversible by normalizing testosterone levels.
Aren't those the very same symptoms that guys have when they are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are a number of drugs which may reduce libido, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also reduce the quantity of the ejaculatory fluid, no wonder. But a reduction in orgasm intensity usually doesn't go together with therapy for BPH. Erectile dysfunction does not ordinarily go along with it either, though certainly if somebody has less sex drive or less attention, it is more of a struggle to have a good erection.
How do you determine whether or not a person is a candidate for testosterone-replacement treatment?
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 these two approaches is far from ideal. Normally guys with the lowest testosterone have the most symptoms and guys with maximum testosterone possess the least. However, there are a number of guys 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 think that's a reasonable guide. But no one quite agrees on a number. It's not like diabetes, where if your fasting glucose is above a certain level, they'll say,"Okay, you've got it." With testosterone, that break point is not quite as clear.
| *Note: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and shouldn't receive my company testosterone therapy. For a hop over to these guys complete copy of the guidelines, log on to www.endo-society.org. |
Is total testosterone the right thing to be measuring? Or should we be measuring something else?
Well, this is another area of confusion and good debate, but I don't think it's as confusing as it appears to be from the literature. When most physicians learned about testosterone in medical school, they heard about overall testosterone, or all of the testosterone in the human 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 available part of total testosterone is called free testosterone, and it is readily available to cells. Though it's just a little fraction of the overall, the free testosterone level is a fairly good indicator of low testosterone. It's not perfect, but the correlation is greater than with testosterone.
Endocrine Society recommendations outlinedThis professional organization recommends testosterone therapy for men who have both Therapy Isn't Suggested for men who have
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Do time of day, diet, or other elements affect testosterone levels?
For years, the recommendation was to get a testosterone value early in the morning since levels begin to drop after 10 or even 11 a.m.. But the data behind this recommendation were drawn from healthy young men. Two recent studies demonstrated little change in blood glucose levels in men 40 and older 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%, a modest sum, and probably not enough to influence identification. Most guidelines still say it is important to perform the evaluation in the morning, but for men 40 and above, it likely doesn't matter much, provided that they get their blood drawn before 6 or 5 p.m.
There are a number of very interesting findings about dietary supplements. For instance, it appears that those who have a diet low in protein have lower testosterone levels than males who consume more protein. But diet has not been studied thoroughly enough to make any recommendations that are clear.
Exogenous vs. endogenous testosteroneWithin this guide, testosterone-replacement therapy refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that's manufactured outside the body. Based upon the formulation, therapy can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, and additional side effects. Preliminary research has proven that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, may foster the creation of natural testosterone, known as endogenous testosterone, in men. Within four to six weeks, each one the guys had heightened levels of testosteronenone reported some side effects throughout the year they had been followed. Because clomiphene citrate is not accepted by the FDA for use in men, little information exists about the long-term ramifications of taking it (including the probability of developing prostate cancer) or whether it is more capable of boosting testosterone than exogenous formulations. But unlike adrenal gland, clomiphene citrate maintains -- and possibly enriches -- sperm production. This makes drugs like clomiphene citrate one of only a few options for men with low testosterone that want to father children. What kinds of testosterone-replacement therapy are available? * The earliest form is an injection, which we still use since it is inexpensive and since we faithfully become good testosterone levels in almost everybody. The drawback is that a man needs to come in every few weeks to get 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 amount of blood glucose. The first form of topical therapy was a patch, but it has a very large rate of skin irritation. In 1 study, as many as 40 percent of people that used the patch developed a reddish area in their skin. That restricts its use. The most commonly used testosterone preparation in the United States -- and the one I start almost everyone off with -- is a topical gel. According to my experience, it has a tendency to be consumed to great levels in about 80% to 85 percent of guys, but leaves a significant number who don't absorb sufficient for it to have a positive effect. [For specifics on various formulations, see table below.] 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 be certain they are absorbing the proper quantity. Our goal is that the mid to upper range of normal, which usually means around 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 two weeks, even although symptoms may not alter for a month or two. |