A Harvard Specialist shares his Ideas on testosterone-replacement therapy
It could be said that testosterone is the thing that makes men, men. It gives them their characteristic deep voices, big 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 normal erections. It also fosters the production of red blood cells, boosts mood, and aids cognition.
Over time, the testicular"machinery" that makes testosterone gradually 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 may start to have signs and symptoms of low testosterone such as lower sex drive and sense of vitality, erectile dysfunction, decreased energy, decreased muscle mass and bone density, and anemia. Taken together, these signs and symptoms are often referred to as hypogonadism ("hypo" meaning low functioning and"gonadism" speaking to the testicles). Yet it's an underdiagnosed issue, with just about 5% of those affected receiving treatment.
But little consensus exists on what constitutes low testosterone, when testosterone supplementation makes sense, or what dangers patients face.
He's developed specific expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment strategies he uses with his patients, and why he believes specialists should rethink the potential link between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt the typical person 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 desire or libido, but another can be erectile dysfunction, and any man who complains of erectile dysfunction should possess his testosterone level checked. Men may experience different symptoms, like more trouble achieving an orgasm, less-intense climaxes, a lesser amount of fluid from ejaculation, and a sense of numbness in the manhood when they see or experience something that would normally be arousing.
The more of these symptoms you will find, the more likely it is that a man has low testosterone. Many physicians tend to dismiss these"soft symptoms" as a normal part of aging, but they're often treatable and reversible by normalizing testosterone levels.
Aren't those the very same symptoms that men have when they are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are quite a few medications that may reduce libido, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the amount of the ejaculatory fluid, no wonder. But a decrease in orgasm intensity usually does not go together with therapy for BPH. Erectile dysfunction does not usually go along with it either, though certainly if a person has less sex drive or less interest, it is more of a challenge to get a good erection.
How do you determine if a man 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 approaches is far from perfect. Generally guys with the lowest testosterone have the most symptoms and men with maximum testosterone possess the least. However, there are a number of guys who have low levels of testosterone in their blood and have no symptoms.
Looking purely at the biochemical amounts, The Endocrine Society* believes low testosterone for a total testosterone level of less than 300 ng/dl, and I think that's a reasonable guide. However, no one quite agrees on a number. It is similar to diabetes, in which if your fasting sugar is above a certain level, they will say,"Okay, you've got it." With testosterone, that break point is not quite as clear.
| *Note: The Endocrine Society recommends clinical practice guidelines with recommendations for who this should and should not receive testosterone therapy. For a Learn More Here complete copy of the Website guidelines, log on to www.endo-society.org. Is complete testosterone the ideal thing to be measuring? Or should we be measuring something else? This is just another area of confusion and great debate, but I do not think that it's as confusing as it appears to be in the literature. When most doctors learned about testosterone in medical school, they heard about total testosterone, or all the testosterone in the human body. But about half of their testosterone that is circulating in the blood is not available to cells. The available part of overall testosterone is called free testosterone, and it's readily available to cells. Almost every lab has a blood test to measure free testosterone. Though it's just a little portion of this overall, the free testosterone level is a pretty good indicator of low testosterone. It's not perfect, but the correlation is greater than with testosterone.
Do time of day, diet, or other factors affect testosterone levels? For many years, the recommendation was to receive a testosterone value early in the morning since levels begin to fall after 10 or even 11 a.m.. However, the information 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 p.m. Between 2 and 6 p.m., it went down by 13 percent, a small sum, and probably insufficient to affect identification. Most guidelines nevertheless say it is important to perform the evaluation in the morning, however for men 40 and over, it probably doesn't matter much, as long as they get their blood drawn before 6 or 5 p.m. There are a number of rather interesting findings about diet. For 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 clear recommendations. Within the following article, testosterone-replacement treatment refers to the treatment of hypogonadism with adrenal gland -- testosterone that's manufactured outside the body. Depending on the formulation, therapy can lead to skin irritation, breast tenderness and enlargement, sleep apnea, acne, reduced sperm count, increased red blood cell count, and other side effects. Preliminary research has shown that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, may boost the production of natural testosterone, known as nitric oxide, in men. At a recent prospective study, 36 hypogonadal men took a daily dose of clomiphene citrate for at least three months. Within four to six months, each one of the guys had increased levels of testosterone; none reported some side effects throughout the year they were followed. Since clomiphene citrate is not approved by the FDA for use in males, little information exists about the long-term ramifications of taking it (such as the probability of developing prostate cancer) or whether it's more capable of boosting testosterone compared to exogenous formulations. But unlike adrenal gland, clomiphene citrate preserves -- and possibly enriches -- sperm production. That makes medication like clomiphene citrate one of just a few choices for men with low testosterone that want to father children. |
What kinds of testosterone-replacement therapy can be found? *
The oldest form is an injection, which we use since it's cheap and because we faithfully get fantastic testosterone levels in nearly everybody. The drawback is that a man should come in every few weeks to find a shot. A roller-coaster effect can also occur as blood glucose levels peak and then return to baseline. [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 in their skin. That restricts its usage.
The most widely used testosterone preparation in the United States -- and the one I start almost everyone off -- is a topical gel. The gel comes from miniature tubes or within a unique dispenser, and you rub it on your shoulders or upper arms once a day. Based on my experience, it tends to be absorbed to great degrees in about 80% to 85 percent of guys, but leaves a substantial number who don't consume sufficient for it to have a favorable impact. [For details on various formulations, see table below.]
Are there any drawbacks to using gels? How much time does it require them to get the job done?
Men who begin using the gels have to return in to have their own testosterone levels measured again to be sure they're absorbing the proper amount. Our target is the mid to upper range of normal, which usually means approximately 500 to 600 ng/dl. The concentration of testosterone in the blood actually goes up quite fast, within several doses. I usually measure it after two weeks, although symptoms may not alter for a month or two.