A Harvard expert shares his thoughts on testosterone-replacement Treatment
A meeting with Abraham Morgentaler, M.D.
It could be stated that testosterone is what makes guys, men. It gives them their characteristic deep voices, big muscles, and facial and body hair, differentiating them from girls. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and leads to normal erections. It also boosts the production of red blood cells, boosts mood, and assists cognition.
Over time, the testicular"machinery" which makes testosterone gradually becomes less powerful, and testosterone levels start to fall, by approximately 1% per year, starting in the 40s. As men get into their 50s, 60s, and beyond, they might start to have symptoms and signs of low testosterone like lower libido and sense of energy, erectile dysfunction, decreased energy, decreased muscle mass and bone density, and nausea. Taken together, these signs and symptoms are often called hypogonadism ("hypo" significance low functioning and"gonadism" referring to the testicles). Researchers estimate that the illness affects anywhere from two to six million men in the United States. Yet it is an underdiagnosed issue, with only about 5% of these affected undergoing therapy.
Studies have revealed that testosterone-replacement therapy can offer a wide selection of advantages for men with hypogonadism, including improved libido, mood, cognition, muscle mass, bone density, and red blood cell production. But little consensus exists about 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 can stimulate prostate cancer.
He's developed specific expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment plans he utilizes his own patients, and why he thinks specialists should rethink the potential connection between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt that the typical person to see a doctor?
As a urologist, I tend to observe guys since they have sexual complaints. The main hallmark of reduced testosterone is low sexual desire or libido, but another can be erectile dysfunction, and some other guy who complains of erectile dysfunction must possess his testosterone level checked. Men can experience other symptoms, such as more difficulty 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 normally be arousing.
The more of these symptoms there are, 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 are 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 precisely. There are quite a few medications that may reduce libido, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the amount of the ejaculatory fluid, no question. However a decrease in orgasm intensity normally 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 a person is a candidate for testosterone-replacement treatment?
There are just two ways that 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 methods is far from perfect. Generally guys with the lowest testosterone have the most symptoms and guys with maximum testosterone possess the least. But there are some men who have reduced levels of testosterone in their blood and have no signs.
Looking purely at the biochemical numbers, The Endocrine Society* believes low testosterone for a total testosterone level of less than 300 ng/dl, and I think that's a sensible guide. However, no one quite agrees on a number. It is similar to diabetes, in which if your fasting glucose is over a certain level, they will 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 my site receive testosterone therapy. Is total testosterone the ideal point to be measuring? Or should we be measuring something else? This is another area of confusion and great discussion, but I don't think it's as confusing as it is apparently in the literature. When most doctors learned about testosterone in medical school, they heard about total testosterone, or all of the testosterone in the human body. But about half of their testosterone that's circulating in the bloodstream isn't readily available to the cells. It is 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. Even though it's just a small portion of the overall, the free testosterone level is a pretty good indicator of low testosterone. It is not perfect, but the significance is greater than with testosterone.
Do time daily, diet, or other factors influence testosterone levels? For years, the recommendation has been to receive a testosterone value early in the morning because levels start to drop after 10 or 11 a.m.. However, 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 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%, a modest sum, and probably insufficient to influence identification. Most guidelines nevertheless say it's important to perform the evaluation in the morning, but for men 40 and above, it likely doesn't matter much, provided that they obtain their blood drawn before 5 or 6 p.m. There are a number of very interesting findings about diet. By way of instance, it appears that individuals that have a diet low in protein have lower testosterone levels than males who consume more protein. But diet hasn't been researched thoroughly enough to make any clear recommendations.
What forms of testosterone-replacement therapy are available? * The oldest form is an injection, which we still use because it's inexpensive and because we reliably get good testosterone levels in nearly everybody. The drawback is that a person should come in every couple of weeks to get a shot. A roller-coaster effect can also occur as blood testosterone levels peak and return to research. Topical therapies help maintain a more uniform level of blood testosterone. The first form of topical treatment has been a patch, but it has a quite high rate of skin irritation. In one 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 in the United States -- and the one I start almost everyone off -- is a topical gel. There are two brands: AndroGel and Testim. Based on my experience, it tends to be consumed to great levels in about 80% to 85% of guys, but leaves a substantial number who do not consume sufficient for it to have a favorable impact. [For specifics on various formulations, see table ] Are there any downsides to using gels? How much time does it require them to get the job done? Men who start using the gels have to return in to have their own testosterone levels measured again to make sure they are absorbing the proper amount. Our goal 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, within several doses. I usually measure it after 2 weeks, even though symptoms may not change for a month or two. |