A Harvard Specialist shares his Ideas on testosterone-replacement therapy
It might be stated that testosterone is what makes men, men. It gives them their characteristic deep voices, large muscles, and body and facial hair, differentiating them from girls. It stimulates the development of the genitals , 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" which produces testosterone slowly becomes less powerful, and testosterone levels start to drop, by about 1% a year, beginning in the 40s. As guys get into their 50s, 60s, and beyond, they may start to have symptoms and signs of low testosterone like reduced libido and sense of energy, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and anemia. Taken together, these signs and symptoms are often called hypogonadism ("hypo" meaning low working and"gonadism" speaking to the testicles). Yet it's an underdiagnosed issue, with just about 5 percent of these affected undergoing therapy.
But little consensus exists about what constitutes low testosterone, when testosterone supplementation makes sense, or what dangers patients face.
He's developed particular expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he uses with his own patients, and he believes 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 have a tendency to observe men because 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 man who complains of erectile dysfunction should get his testosterone level checked. Men can experience different symptoms, such as more difficulty achieving an orgasm, less-intense climaxes, a much smaller amount of fluid out of ejaculation, and a sense of numbness in the manhood when they see or experience something that would normally be arousing.
The more of the symptoms you will find, the more probable it is that a man has low testosterone. Many physicians tend to dismiss those"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 drugs 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 wonder. But a decrease in orgasm intensity usually doesn't 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's more of a struggle to get a fantastic erection.
How do you decide if a person is a candidate for testosterone-replacement therapy?
There are just two ways that we determine whether someone has reduced testosterone. One is a blood test and the other is by characteristic signs and symptoms, and the correlation between those two approaches is far from perfect. Normally guys with the lowest testosterone have the most symptoms and men with highest testosterone possess the least. But there are a number of guys who have low levels of testosterone in their blood and have no signs.
Looking 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's a sensible guide. But no one quite agrees on a few. It's similar to diabetes, where if your fasting sugar is over a certain level, they'll say,"Okay, you've got it." With testosterone, that break point is not quite as clear.
| *Notice: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and shouldn't receive testosterone treatment. |
Is complete testosterone the ideal thing to be measuring? Or if we are measuring something else?
Well, this is another area of confusion and good discussion, but I don't think it's as confusing as it is apparently from the literature. When most physicians learned about testosterone in medical school, they learned about total testosterone, or all of the testosterone in the human body. However, about half of the testosterone that is circulating in the bloodstream is not readily available to 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 is readily available to cells. Almost every lab has a blood test to measure free testosterone. Though it's just a little portion of the total, the free testosterone level is a pretty good indicator of reduced testosterone. It is not ideal, but the significance is greater than with total testosterone.
This professional organization urges testosterone therapy for men who have both
- Low levels of testosterone in the blood (less than 300 ng/dl)
- symptoms of low testosterone.
Therapy is not Suggested for men who've
- Breast or prostate cancer
- a nodule on the prostate that can be felt during a DRE
- a PSA greater than 3 ng/ml without further analysis
- that a hematocrit greater than 50 percent or thick, viscous blood
- untreated obstructive sleep apnea
- severe lower urinary tract infections
- class III or IV article sourcemy website heart failure. over at this website
Do time of day, diet, or other factors affect testosterone levels?
For years, the recommendation has been to get a testosterone value early in the morning because levels start to drop after 10 or 11 a.m.. But the data behind this recommendation were attracted to healthy young men. Two recent studies demonstrated little change in blood glucose levels in men 40 and mature within the course of this day. One reported no change in typical testosterone till after 2 p.m. Between 2 and 6 p.m., it went down by 13%, a modest amount, and probably not enough to affect diagnosis. Most guidelines nevertheless say it's important to do the test in the morning, but for men 40 and over, it likely does not matter much, as long as they get their blood drawn before 5 or 6 p.m.
There are some rather interesting findings about dietary supplements. By way of example, it appears that those that 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.
FormulationsExogenous vs. endogenous testosterone
In this article, testosterone-replacement treatment refers to the treatment of hypogonadism with adrenal gland -- testosterone that's manufactured outside the body. Depending on the formulation, treatment can lead to skin irritation, breast tenderness and enlargement, sleep apnea, acne, decreased sperm count, increased red blood cell count, and other side effects.
Preliminary research has 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, all the men had increased levels of testosterone; none reported some side effects during the entire year they were followed.
Since clomiphene citrate is not accepted by the FDA for use in men, little information exists regarding the long-term ramifications of taking it (including the risk of developing prostate cancer) or whether it is more effective at boosting testosterone than exogenous formulas. But unlike adrenal gland, clomiphene citrate preserves -- and potentially enhances -- sperm production. That makes drugs like clomiphene citrate one of just a few choices for men with low testosterone that wish to father children.
What kinds of testosterone-replacement treatment are available? *
The earliest form is the injection, which we use because it is 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 may also occur as blood glucose levels peak and return to research. [See"Exogenous vs. endogenous testosterone," above.]
Topical therapies help preserve a more uniform level of blood glucose. The first form of topical treatment has been a patch, but it has a very large rate of skin irritation. In one study, as many as 40 percent of people that used the patch developed a red area on their skin. That restricts its use.
The most widely used testosterone preparation in the United States -- and the one I begin almost everyone off with -- is a topical gel. There are just two brands: AndroGel and Testim. According to my experience, it tends to be absorbed to great levels in about 80% to 85% of guys, but that leaves a substantial number who do not consume enough for this to have a favorable effect. [For details on various formulations, see table ]
Are there any drawbacks to using dyes? How much time does it take for them to get the job done?
Men who begin using the gels have to return in to have their own testosterone levels measured again to make certain they are absorbing the right quantity. 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 blood really goes up quite fast, within a few doses. I normally measure it after 2 weeks, even though symptoms may not change for a month or two.