A Harvard Specialist shares his Ideas on testosterone-replacement therapy
It might be stated that testosterone is what makes men, men. It gives them their characteristic deep voices, large muscles, and body and facial hair, differentiating them from girls. It stimulates the development of the genitals at puberty, plays a role in sperm production, fuels libido, and contributes to regular erections. Additionally, it boosts the production of red blood cells, boosts mood, and aids cognition.
Over time, the "machinery" which produces testosterone slowly becomes less effective, and testosterone levels start to fall, by about 1 percent a year, beginning in the 40s. As men get into their 50s, 60s, and beyond, they might start to have signs and symptoms of low testosterone such as lower sex drive and sense of vitality, erectile dysfunction, decreased energy, reduced muscle mass and bone density, and anemia. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" significance low working and"gonadism" referring to the testicles). Yet it is an underdiagnosed problem, with only about 5% of these affected undergoing therapy.
Various studies have revealed that testosterone-replacement therapy can offer a wide range of advantages for men with hypogonadism, such as enhanced libido, mood, cognition, muscle mass, bone density, and red blood cell production. Much of the current debate focuses on the long-held belief that testosterone can 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 ailments and male reproductive and sexual difficulties. He has developed specific experience in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment strategies he utilizes his patients, and he believes specialists should rethink the possible connection between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt that the typical man to find a physician?
As a urologist, I have a tendency to observe men because they have sexual complaints. The main hallmark of low testosterone is low 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 amount of fluid from ejaculation, and a sense of numbness in the penis when they see or experience something that would normally be arousing.
The more of the symptoms there are, the more likely it is that a man has low testosterone. Many physicians often dismiss those"soft symptoms" as a normal part of aging, but they're often treatable and reversible by decreasing testosterone levels.
Aren't those the very same symptoms that men have when they are treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are a number of medications that may reduce libido, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs can also reduce the amount of the ejaculatory fluid, no question. But a decrease in orgasm intensity usually doesn't go together with therapy for BPH. Erectile dysfunction does not usually go together with it either, though surely if somebody has less sex drive or less attention, it's more of a struggle to get a fantastic erection.
How do you decide whether a person is a candidate for testosterone-replacement therapy?
There are just two ways that we determine whether someone has low testosterone. One is a blood test and the other one is by characteristic symptoms and signs, and the correlation between those two methods is far from ideal. Generally guys with the lowest testosterone have the most symptoms and men with highest testosterone possess the least. But there are a number of men who have reduced levels of testosterone in their blood and have no symptoms.
Looking at the biochemical numbers, The Endocrine Society* believes low testosterone to be a entire testosterone level of less than 300 ng/dl, and I think that is a reasonable guide. However, no one quite agrees on a few. It's not like diabetes, in which if your fasting glucose 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 publishes clinical practice guidelines with recommendations for who should and should link not receive testosterone therapy. sites For a complete copy of these guidelines, log helpful resources on to www.endo-society.org. Is complete testosterone the ideal thing to be measuring? Or should we be measuring something different? This is another area of confusion and good discussion, but I don't think it's as confusing as it is apparently from the literature. When most doctors learned about testosterone in medical school, they heard about overall testosterone, or all the testosterone in the body. But about half of their testosterone that is circulating in the bloodstream isn't readily available to the cells. It's closely bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG. The biologically available part of total testosterone is known as free testosterone, and it's readily available to the cells. Almost every laboratory has a blood test to measure free testosterone. Though it's only a small fraction of the overall, the free testosterone level is a fairly good indicator of reduced testosterone. It's not perfect, but the correlation is greater compared to testosterone. This professional organization urges testosterone therapy for men who have both
Therapy Isn't Suggested for men who've
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Do time of day, diet, or other factors affect testosterone levels?
For years, the recommendation has been to get a testosterone value early in the morning because levels start to drop after 10 or 11 a.m.. But the data behind that recommendation were drawn from healthy young men. Two recent studies showed little change in blood testosterone levels in men 40 and older over the course of the day. One reported no change in average testosterone until after 2 Between 2 and 6 p.m., it went down by 13%, a modest amount, and probably not enough to influence diagnosis. Most guidelines still say it's important to do the test in the morning, but for men 40 and over, it likely does not matter much, provided that they get their blood drawn before 6 or 5 p.m.
There are a number of very interesting findings about diet. For instance, it seems that those that have a diet low in protein have lower testosterone levels than men who consume more protein. But diet hasn't been researched thoroughly enough to create any clear recommendations.
Exogenous vs. endogenous testosteroneIn 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, treatment can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, along with other side effects. Within four to six months, all of the guys had heightened levels of testosterone; none reported some side effects throughout the year they were followed. Since clomiphene citrate isn't approved by the FDA for use in males, little information exists about the long-term effects of taking it (such as the risk of developing prostate cancer) or whether it's more effective at boosting testosterone than exogenous formulations. But unlike adrenal gland, clomiphene citrate preserves -- and possibly enriches -- sperm production. That makes drugs such as clomiphene citrate one of only a few choices for men with low testosterone that wish to father children. What kinds of testosterone-replacement therapy are available? * The earliest form is the injection, which we still use since it is inexpensive and since we reliably become good testosterone levels in almost everybody. The disadvantage is that a man should come in every few weeks to find a shot. A roller-coaster effect can also happen as blood testosterone levels peak and then return to research. [See"Exogenous vs. endogenous testosterone," above.] Topical treatments help maintain a more uniform amount of blood testosterone. The first kind of topical therapy has been a patch, but it has a very large rate of skin irritation. In one study, as many as 40 percent of men who used the patch developed a reddish area on their skin. That restricts its use. The most widely used testosterone preparation in the United States -- and also the one I start almost everyone off -- is a topical gel. Based on my experience, it has a tendency to be absorbed to great degrees in about 80% to 85% of guys, but that leaves a significant number who do not absorb sufficient for it 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 get the job done? Men who start using the implants need to come back in to have their testosterone levels measured again to make certain they're absorbing the right quantity. Our target 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 fast, in just a few doses. I usually measure it after 2 weeks, even though symptoms may not change for a month or two. |