It could be said that testosterone is what 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 powerful, and testosterone levels begin to drop, by approximately 1 percent per year, starting in the 40s. As guys get in their 50s, 60s, and beyond, they might start to have symptoms and signs of low testosterone like lower sex drive and sense of vitality, erectile dysfunction, decreased energy, reduced muscle mass and bone density, and anemia. Taken together, these signs and symptoms are often called hypogonadism ("hypo" meaning low functioning and"gonadism" referring to the testicles). Yet it is an underdiagnosed problem, with only about 5% of those 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 ailments and male reproductive and sexual problems. He's developed specific experience in treating low testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment strategies he utilizes his own patients, and why he thinks experts should reconsider the possible connection between testosterone-replacement treatment and prostate cancer.Symptoms and diagnosis
What symptoms and signs of low testosterone prompt the average man to find a physician?
As a urologist, I tend to see guys since they have sexual complaints. The primary hallmark of reduced testosterone is reduced sexual libido or desire, but another can be erectile dysfunction, and any guy who complains of erectile dysfunction must get his testosterone level checked. Men may experience different symptoms, like more trouble achieving an orgasm, less-intense orgasms, a lesser quantity of fluid from ejaculation, and a feeling of numbness in the penis when they see or experience something which would usually be arousing.
The more of the symptoms there are, the more likely it is that a man has low testosterone. Many physicians tend to discount those"soft symptoms" as a normal part of aging, but they are often treatable and reversible by normalizing testosterone levels.
Are not those the very same symptoms that guys have when they are treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are quite a few drugs which may reduce libido, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs can also reduce the amount of the ejaculatory fluid, no wonder. However a reduction in orgasm intensity normally does not go along with therapy for BPH. Erectile dysfunction does not usually go together with it either, though surely if somebody has less sex drive or less attention, it is more of a challenge to have a fantastic erection.
How do you decide whether or not a man is a candidate for testosterone-replacement treatment?
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 these two methods is far from ideal. Generally guys with the lowest testosterone have the most symptoms and men with maximum testosterone have the least. However, there are some 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 to be a entire testosterone level of less than 300 ng/dl, and I think that is a reasonable guide. However, no one quite agrees on a few. It is similar to diabetes, where if your fasting glucose 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 should not receive testosterone therapy. Watch"Endocrine Society recommendations summarized."|
Is total testosterone the ideal point to be measuring? Or if we are measuring something different?
Well, this is 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 learned about total testosterone, or all of the testosterone in the body. But about half of their testosterone that's circulating in the blood isn't available to the cells. It's tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG.
The available part of total testosterone is known as free testosterone, and it's readily available to cells. Though it's only a little portion of this overall, the free testosterone level is a pretty good indicator of low testosterone. It is not perfect, but the significance is greater compared to total testosterone.
Endocrine Society recommendations outlined
This professional organization urges testosterone treatment for men who have
Therapy is not Suggested for men who've
What kinds of testosterone-replacement therapy can be found? *
The oldest form is an injection, which we use since it's cheap and since we reliably become fantastic testosterone levels in nearly everybody. The drawback is that a man should come in every couple of weeks to get a shot. A roller-coaster effect may also occur as blood glucose levels peak and return to research. [See"Exogenous vs. endogenous testosterone," above.]
Topical treatments help preserve a more uniform level of blood glucose. The first form of topical treatment was a patch, but it has a quite high rate of skin irritation. In 1 study, as many as 40% of people that used the patch developed a reddish area on their skin. That restricts its use.
The most widely used testosterone preparation in the United States -- and also the one I start almost everyone off -- is a topical gel. The gel comes in tiny tubes or within a special 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 levels in about 80% to 85% of men, but that leaves a significant number who don't consume enough for this to have a positive impact. [For specifics on several different formulations, see table below.]
Are there any downsides to using gels? How much time does it require them to work?
Men who begin using the gels have to come back in to have their own testosterone levels measured again to make sure they are absorbing the right amount. Our goal is the mid to upper range of normal, which generally means around 500 to 600 ng/dl. The concentration of testosterone in the blood really goes up quite quickly, within several doses. I usually measure it after two weeks, even though symptoms may not change for a month or two.