A Harvard expert shares his thoughts on testosterone-replacement therapy
It could be said that testosterone is the thing that makes guys, guys. 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 normal erections. Additionally, it boosts the production of red blood cells, boosts mood, and aids cognition.
As time passes, the "machinery" which makes testosterone gradually becomes less powerful, and testosterone levels begin to fall, by about 1 percent a year, beginning in the 40s. As guys get into their 50s, 60s, and beyond, they may begin to have symptoms and signs of low testosterone such as lower libido and sense of vitality, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often called hypogonadism ("hypo" significance low working and"gonadism" referring to the testicles). Yet it is an underdiagnosed issue, with just about 5 percent of these affected receiving treatment.
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 diseases and male sexual and reproductive problems. He has developed specific expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment plans he uses with his patients, and he thinks experts should reconsider the possible link between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt that the average person to see a physician?
As a urologist, I tend to observe guys because they have sexual complaints. The main hallmark of low testosterone is reduced sexual desire or libido, but another may be erectile dysfunction, and some other man who complains of erectile dysfunction must possess his testosterone level checked. Men may experience other symptoms, like more difficulty achieving an orgasm, less-intense orgasms, a much smaller amount of fluid out of ejaculation, and a feeling of numbness in the penis when they see or experience something which 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, however, they're often treatable and reversible by normalizing testosterone levels.
Are not those the very same symptoms that men have when they're treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are a number of medications that may reduce libido, including 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 normally does not go along with treatment for BPH. Erectile dysfunction does not ordinarily go together with it either, though certainly if somebody has less sex drive or less attention, it is more of a challenge to get a good erection.
How can you decide if or not a person is a candidate for testosterone-replacement treatment?
There are just two ways that we determine whether somebody has low testosterone. One is a blood test and the other is by characteristic signs and symptoms, and the correlation between these two approaches is far from perfect. Generally men with the lowest testosterone have the most symptoms and men with highest 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 numbers, The Endocrine Society* considers low testosterone to be a entire testosterone level of less than 300 ng/dl, and I believe that is a sensible guide. However, no one really agrees on a few. It is similar to diabetes, where if your fasting sugar is over a certain level, they will say,"Okay, you've got it." With testosterone, that break point isn't quite as apparent.
| *Notice: The Endocrine Society recommends clinical practice guidelines with recommendations for who visit this web-site should and website link should not receive testosterone treatment. 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 do not think that it's as confusing as it is apparently 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 biologically available part of total testosterone is known as free testosterone, and it is readily available to cells. Though it's just a small fraction of the overall, the free testosterone level is a fairly good indicator of reduced testosterone. It's not ideal, but the correlation is greater compared to total testosterone.
Do time of day, diet, or other factors influence testosterone levels? For many years, the recommendation has been to receive a testosterone value early in the morning since levels start to fall after 10 or even 11 a.m.. But the information behind this recommendation were attracted to healthy young men. Two recent studies demonstrated little change in blood testosterone 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 2 and 6 p.m., it went down by 13 percent, a modest sum, and probably insufficient to influence identification. Most guidelines nevertheless say it's important to perform the test in the morning, however for men 40 and over, it probably does not matter much, as long as they get their blood drawn before 6 or 5 p.m. There are some rather interesting findings about diet. By way of instance, it appears that individuals that have a diet low in protein have lower testosterone levels than men who eat more protein. But diet has not been studied thoroughly enough to create any clear recommendations.
What kinds of testosterone-replacement therapy are available? * The earliest form is the injection, which we still use because it is cheap and since we reliably get fantastic testosterone levels in almost everybody. The disadvantage is that a man should come in every couple of weeks to get a shot. A roller-coaster effect can also happen as blood glucose levels peak and then return to research. Topical therapies help maintain a more uniform amount of blood glucose. The first form of topical therapy was a patch, but it has a quite large rate of skin irritation. In 1 study, as many as 40% of men who used the patch developed a red area in their skin. That limits its usage. The most widely used testosterone preparation from the United States -- and the one I start almost everyone off with -- is a topical gel. There are two brands: AndroGel and Testim. Based on my experience, it has a tendency to be consumed to good levels in about 80% to 85 percent of guys, but leaves a substantial number who do not consume sufficient for this to have a positive effect. [For details on several different formulations, see table ] Are there any drawbacks to using dyes? How long does it take for them to get the job done? Men who begin using the implants need to return in to have their own testosterone levels measured again to be certain they're absorbing the right 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 blood actually goes up quite quickly, within several doses. I normally measure it after 2 weeks, even although symptoms may not alter for a month or two. |