A Harvard Specialist shares his Ideas on testosterone-replacement therapy
It could 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 women. It stimulates the growth of the genitals at puberty, plays a role in sperm production, fuels libido, and leads to normal erections. Additionally, it boosts the production of red blood cells, boosts mood, and aids cognition.
As time passes, the "machinery" that makes testosterone gradually becomes less powerful, and testosterone levels start to fall, by approximately 1% a year, beginning in the 40s. As men get in their 50s, 60s, and beyond, they may start to have signs and symptoms of low testosterone like reduced sex drive and sense of energy, erectile dysfunction, decreased energy, decreased muscle mass and bone density, and anemia. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" meaning low working and"gonadism" referring to the testicles). Yet it's an underdiagnosed issue, with only about 5% of these affected receiving treatment.
Studies have shown that testosterone-replacement therapy may provide a wide range of benefits for men with hypogonadism, such as improved libido, mood, cognition, muscle mass, bone density, and red blood cell production. 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.
He's developed specific experience in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he utilizes his own patients, and why he believes experts should reconsider the possible connection between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt the typical person to see a doctor?
As a urologist, I tend to see guys because they have sexual complaints. The primary hallmark of reduced testosterone is low sexual desire or libido, but another may be erectile dysfunction, and any guy who complains of erectile dysfunction must possess his testosterone level checked. Men may experience other 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 usually be arousing.
The more of the symptoms you will find, the more likely it is that a man has low testosterone. Many physicians often discount these"soft symptoms" as a normal part of aging, but they're 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 quite a few medications which may lessen sex drive, such as the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the amount of the ejaculatory fluid, no question. But a decrease in orgasm intensity usually doesn't go along with treatment for BPH. Erectile dysfunction does not usually go along with it , though surely if a person has less sex drive or less attention, it's more of a challenge to have a good erection.
How can you determine whether or not a person is a candidate for testosterone-replacement therapy?
There are two ways we determine whether someone has reduced testosterone. One is a blood test and the other is by characteristic symptoms and signs, 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 a number of men who have reduced levels of testosterone in their blood and have no signs.
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 is a sensible guide. But 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 recommends clinical practice guidelines with recommendations for who should and shouldn't receive testosterone therapy. Watch"Endocrine more helpful hints Society recommendations summarized." Is total testosterone the ideal thing to be measuring? Or should we be measuring something else? Well, this is another area of confusion and good discussion, but I don't think that it's as confusing as it is apparently in the literature. When most physicians learned about testosterone in medical school, they learned about total testosterone, or all of the testosterone in the body. However, about half of their testosterone that is circulating in the blood is not available to cells. The available part of overall testosterone is known as free testosterone, and it's readily available to cells. Even though it's only a small portion of the overall, the free testosterone level is a pretty good indicator of low testosterone. It is not perfect, but the correlation is greater than with total testosterone.
Do time of day, diet, or other factors influence testosterone levels? For years, the recommendation was to get a testosterone value early in the morning since levels begin to fall after 10 or even 11 a.m.. But the information behind this recommendation were drawn from healthy young men. Two recent studies showed little change in blood glucose levels in men 40 and mature within the course of this day. One reported no change in average testosterone until after 2 Between 6 and 2 p.m., it went down by 13 percent, a modest amount, and probably not enough to affect diagnosis. Most guidelines still say it's important to do the evaluation in the morning, but for men 40 and above, it probably does not matter much, as long as they get their blood drawn before 5 or 6 p.m. There are some very interesting findings about diet. By way of instance, it appears that those who 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 make any clear recommendations. In the following guide, testosterone-replacement therapy refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that's produced outside the body. Based upon the formula, therapy can cause skin irritation, breast tenderness and enlargement, sleep apnea, acne, reduced sperm count, increased red blood cell count, along with additional side effects. Preliminary studies have shown that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, may foster the production of natural testosterone, also termed nitric oxide, in men. Within four to six months, each one the guys had increased levels of testosteronenone reported any side effects during the entire year they were followed. Because clomiphene citrate isn't approved by the FDA for use in males, little information exists regarding the long-term effects of carrying it (including the risk 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 enhances -- sperm production. This 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 are available? *
The oldest form is an injection, which we still use because it is inexpensive and since we reliably become fantastic testosterone levels in almost everybody. The disadvantage is that a man should come in every couple of weeks to find a shot. A roller-coaster effect can also happen as blood glucose levels peak and return to research. [See"Exogenous vs. endogenous testosterone," above.]
Topical therapies help maintain a more uniform amount of blood glucose. The first kind of topical therapy has been a patch, but it has a quite high rate of skin irritation. In 1 study, as many as 40% of men who used the patch developed a red area on their skin. That restricts its usage.
The most commonly used testosterone preparation from the United States -- and also the one I begin almost everyone off with -- is a topical gel. The gel comes in miniature tubes or within a unique dispenser, and you rub it on your shoulders or upper arms once a day. According to 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 don't absorb enough for this to have a positive impact. [For details on various formulations, see table ]
Are there any drawbacks to using gels? How long does it require them to get the job done?
Men who begin using the implants need to return in to have their 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 around 500 to 600 ng/dl. The concentration of testosterone in the blood really goes up quite quickly, in just several doses. I usually measure it after two weeks, even although symptoms may not alter for a month or two.