A Harvard Specialist shares his thoughts on testosterone-replacement therapy
It might be stated that testosterone is the thing that makes men, men. It gives them their characteristic deep voices, big muscles, and facial and body hair, differentiating them from women. It stimulates the development of the genitals , plays a role in sperm production, fuels libido, and leads to normal erections. Additionally, it fosters the production of red blood cells, boosts mood, and assists cognition.
As time passes, the "machinery" which produces testosterone slowly becomes less effective, and testosterone levels start to drop, by approximately 1 percent a year, starting in the 40s. As guys get into their 50s, 60s, and beyond, they might begin to have signs and symptoms of low testosterone like reduced sex drive and sense of energy, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" meaning low working and"gonadism" speaking to the testicles). Yet it's an underdiagnosed problem, with only about 5 percent of these affected receiving treatment.
But little consensus exists about what constitutes low testosterone, when testosterone supplementation makes sense, or what dangers patients face.
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 reproductive and sexual difficulties. He has developed particular experience in treating low testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment plans he utilizes 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 man to see a doctor?
As a urologist, I tend to observe guys since 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 get his testosterone level checked. Men may experience other symptoms, such as more difficulty achieving an orgasm, less-intense orgasms, a smaller amount of fluid from ejaculation, and a feeling of numbness in the penis when they see or experience something that 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, however, they are often treatable and reversible by normalizing testosterone levels.
Aren't those the very 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, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the amount of the ejaculatory fluid, no wonder. However a decrease in orgasm intensity normally does not go along with therapy for BPH. Erectile dysfunction does not usually go along with it either, though surely if a person has less sex drive or less attention, it's more of a challenge to get a fantastic erection.
How can you decide 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 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. However, there are some men who have reduced levels of testosterone in their blood and have no symptoms.
Looking at the biochemical amounts, The Endocrine Society* believes low testosterone to be a total testosterone level of less than 300 ng/dl, and I believe that is a reasonable guide. However, no one really agrees on a number. It is similar to diabetes, where if your fasting glucose is over a certain level, they will say,"Okay, you've got it." With testosterone, that break point is not quite as apparent.
| *Notice: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and should not receive testosterone treatment. For a click here for more info complete copy of the guidelines, log on to www.endo-society.org. Is complete testosterone the ideal thing to be measuring? Or if we are measuring something else? Well, this is just another area of confusion and great debate, but I do not think it's as confusing as it is apparently from 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's circulating in the blood is not readily available to the cells. It's closely bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG. The biologically available part of overall testosterone is known as free testosterone, and it's readily available to cells. Though it's only a little fraction of this total, 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.
What forms of testosterone-replacement therapy are available? * The earliest form is the injection, which we use because it's cheap and since we faithfully become good testosterone levels in nearly everybody. The disadvantage is that a person should come in every couple of weeks to get a shot. A roller-coaster effect can also occur as blood glucose levels peak and return to baseline. Topical therapies help preserve a more uniform amount of blood glucose. The first form of topical therapy has been a patch, but it has a quite high rate of skin irritation. In one study, as many as 40 percent of people that used the patch developed a reddish area on their skin. That limits 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 in miniature tubes or within a special dispenser, and you rub it on your shoulders or upper arms once a day. Based on my experience, it has a tendency to be consumed to good levels in about 80% to 85 percent of men, but that leaves a significant number who do not absorb sufficient for this to have a positive impact. [For details on various formulations, see table below.] Are there any downsides to using dyes? How long does it require them to work? Men who start using the implants need to come back in to have their testosterone levels measured again to be 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 actually goes up quite fast, within several doses. I usually measure it after 2 weeks, although symptoms may not change for a month or two. |