A Harvard Specialist shares his thoughts on testosterone-replacement Treatment
It could be said 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.
As time passes, the "machinery" which produces testosterone slowly becomes less powerful, and testosterone levels begin to drop, by approximately 1 percent per year, beginning in the 40s. As men get into their 50s, 60s, and beyond, they may start to have signs and symptoms of low testosterone such as lower sex drive and sense of energy, erectile dysfunction, diminished energy, decreased muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" significance low working and"gonadism" referring to the testicles). Researchers estimate that the condition affects anywhere from two to six million men in the United States. Yet it is an underdiagnosed problem, with only about 5% of these affected undergoing therapy.
But little consensus exists on 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 may stimulate prostate cancer.
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 experts should reconsider the potential connection between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt that the typical man to see a physician?
As a urologist, I tend to see guys because they have sexual complaints. The primary 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 must possess his testosterone level checked. Men may experience different 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 discount those"soft symptoms" as a normal part of aging, however, they are often treatable and reversible by decreasing testosterone levels.
Are not those the same symptoms that guys have when they're treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are a number of medications that may lessen sex drive, such as the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs may also decrease the quantity of the ejaculatory fluid, no question. However a reduction in orgasm intensity normally does not go together with treatment for BPH. Erectile dysfunction does not ordinarily go along with it , though certainly if a person has less sex drive or less interest, it is more of a challenge to have a good erection.
How can you determine whether or not a man is a candidate for testosterone-replacement treatment?
There are two ways we determine whether somebody 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 ideal. Generally guys with the lowest testosterone have the most symptoms and men with maximum testosterone possess the least. But there are a number of men who have low levels of testosterone in their blood and have no signs.
Looking purely at the biochemical amounts, The Endocrine Society* considers 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 really agrees on a number. It is similar to diabetes, where if your fasting sugar is above a certain level, they'll say,"Okay, you've got it." With testosterone, that break point isn't quite as apparent.
| *Note: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and should investigate this site not receive testosterone treatment. For a complete copy of these guidelines, log Full Articlefind out this here on to www.endo-society.org. |
Is complete testosterone the ideal thing to be measuring? Or should we be measuring something different?
This is another area of confusion and great discussion, but I do not think it's as confusing as it appears to be from the literature. When most physicians learned about testosterone in medical school, they heard about total testosterone, or all the testosterone in the human body. However, about half of their testosterone that is circulating in the blood is not available to the cells. It is closely bound to a carrier molecule known as 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. Almost every laboratory has a blood test to measure free testosterone. Though it's just a little fraction of the total, the free testosterone level is a fairly good indicator of reduced testosterone. It is not ideal, but the correlation is greater than with total testosterone.
This professional organization urges testosterone treatment for men who have both
- Low levels of testosterone in the blood (less than 300 ng/dl)
- symptoms of low testosterone.
Therapy Isn't Suggested for men who've
- Breast or prostate cancer
- a nodule on the prostate which may be felt during a DRE
- that a PSA higher than 3 ng/ml without additional analysis
- that a hematocrit greater than 50 percent or thick, viscous blood
- untreated obstructive sleep apnea
- severe lower urinary tract symptoms
- class III or IV heart failure.
Do time of day, diet, or other factors affect testosterone levels?
For many years, the recommendation was to receive a testosterone value early in the morning since levels begin to fall after 10 or even 11 a.m.. However, the information behind this recommendation were attracted to healthy young men. Two recent studies demonstrated little change in blood glucose levels in men 40 and older over 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 insufficient to affect identification. Most guidelines nevertheless say it is important to perform the evaluation in the morning, however for men 40 and above, it probably doesn't 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 instance, it appears that individuals who have a diet low in protein have lower testosterone levels than men who eat more protein. But diet has not been researched thoroughly enough to make any recommendations that are clear.
Exogenous vs. endogenous testosteroneIn the following guide, testosterone-replacement treatment refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that is manufactured outside the body. Based upon the formula, treatment can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, along with additional side effects. Within four to six months, all of the guys had heightened levels of testosterone; none reported some side effects throughout the year they were followed. Since clomiphene citrate is not accepted by the FDA for use in males, little information exists about the long-term effects of carrying it (including the risk of developing prostate cancer) or if it is more effective at boosting testosterone compared to exogenous formulas. But unlike exogenous testosterone, clomiphene citrate maintains -- and potentially enhances -- sperm production. This makes drugs like clomiphene citrate one of just a few choices for men with low testosterone that want to father children. |
What kinds of testosterone-replacement treatment are available? *
The earliest form is an injection, which we use since it's cheap and because we reliably get good testosterone levels in almost everybody. The disadvantage is that a person needs to come in every couple of weeks to get a shot. A roller-coaster effect may also occur as blood glucose levels peak and then return to research. [See"Exogenous vs. endogenous testosterone," above.]
Topical treatments help maintain a more uniform amount of blood testosterone. The first kind of topical therapy has been a patch, but it has a very large rate of skin irritation. In one study, as many as 40% 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. According to my experience, it tends to be consumed to great levels in about 80% to 85 percent of men, but that leaves a significant number who don't absorb sufficient for it to have a positive impact. [For specifics on several different formulations, see table below.]
Are there any drawbacks to using dyes? How long does it take for them to work?
Men who begin using the implants need to come back in to have their testosterone levels measured again to be certain they're absorbing the right quantity. Our goal is that the mid to upper range of normal, which generally means approximately 500 to 600 ng/dl. The concentration of testosterone in the blood actually goes up quite fast, in just several doses. I usually measure it after two weeks, although symptoms may not change for a month or two.