A Harvard expert shares his thoughts on testosterone-replacement Treatment
A meeting with Abraham Morgentaler, M.D.
It could be stated that testosterone is the thing that makes men, guys. It gives them their characteristic deep voices, large muscles, and body and facial hair, distinguishing them from girls. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and contributes to regular erections. It also boosts the production of red blood cells, boosts mood, and assists cognition.
Over time, the "machinery" that produces testosterone slowly becomes less effective, and testosterone levels begin to drop, by about 1 percent per year, beginning in the 40s. As guys get in their 50s, 60s, and beyond, they may start to have symptoms and signs of low testosterone such as reduced libido and sense of vitality, erectile dysfunction, diminished energy, decreased muscle mass and bone density, and nausea. Taken together, these signs and symptoms are often referred to as hypogonadism ("hypo" significance low functioning and"gonadism" referring to the testicles). Yet it is an underdiagnosed issue, with just about 5% of those affected undergoing therapy.
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 uses with his own 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 average man to see a doctor?
As a urologist, I tend to see guys since they have sexual complaints. The main hallmark of reduced testosterone is reduced sexual libido or desire, but another may be erectile dysfunction, and some other guy who complains of erectile dysfunction must possess his testosterone level checked. Men can experience different symptoms, like more trouble achieving an orgasm, less-intense climaxes, a much lesser quantity 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 those"soft symptoms" as a normal part of aging, however, they're often treatable and reversible by decreasing testosterone levels.
Are not those the very same symptoms that guys have when they're treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are quite a few medications which may reduce libido, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the amount of the ejaculatory fluid, no question. However a decrease in orgasm intensity normally does not go along with treatment for BPH. Erectile dysfunction does not usually go together with it , though certainly if a person has less sex drive or less attention, it's more of a challenge to get a good erection.
How can you decide whether a man 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 symptoms and signs, and the correlation between those two approaches is far from ideal. Generally men with the lowest testosterone have the most symptoms and guys with maximum testosterone have the least. But there are a number of guys who have low levels of testosterone in their blood and have no symptoms.
Looking at the biochemical numbers, The Endocrine Society* believes low testosterone for 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.
| *Note: The Endocrine Society publishes clinical practice guidelines with recommendations for who should next page and should not receive testosterone therapy. For a complete copy of these instructions, log on to www.endo-society.org. |
Is complete testosterone the right point to be measuring? Or if we are measuring something else?
This is another area of confusion and good debate, but I don't think that it's as confusing as it appears to be from the literature. When most doctors learned about testosterone in medical school, they heard about total testosterone, or all of 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 is tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG.
The biologically available portion of total 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 low testosterone. It is not ideal, but the correlation is greater compared to total testosterone.
This professional organization urges testosterone therapy for men who have
- Reduced 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 may be felt during a DRE
- a PSA higher than 3 ng/ml without additional evaluation
- that a hematocrit greater than 50% or thick, viscous blood
- untreated obstructive sleep apnea
- severe lower urinary tract infections
- class III or IV heart failure.
Do time daily, diet, or other elements affect testosterone levels?
For many years, the recommendation has been to get a testosterone value early in the morning since levels start to drop after 10 or even 11 a.m.. However, the data behind that recommendation were attracted to healthy young men. Two recent studies showed little change in blood testosterone levels in men 40 and mature over the course of the day. One reported no change in typical testosterone till after 2 p.m. Between 2 and 6 p.m., it went down by 13 percent, a small amount, and probably not enough to affect diagnosis. Most guidelines still say it's important to perform the evaluation in the morning, but for men 40 and above, it likely does not matter much, as long as they get their blood drawn before 6 or 5 p.m.
There are a number of very interesting findings about diet. By way of instance, it appears that individuals who have a diet low in protein have lower testosterone levels than men who consume more protein. But diet has not been researched thoroughly enough to create any clear recommendations.
Within the following guide, testosterone-replacement therapy refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that is produced outside the body. Based upon the formula, treatment can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, reduced sperm count, increased red blood cell count, along with additional side effects.
Within four to six weeks, all the men had heightened levels of testosterone; none reported any side effects during the year they were followed.
Because clomiphene citrate is not approved by the FDA for use in men, little information exists about the long-term effects of carrying it (such as the probability of developing prostate cancer) or if it's more capable of boosting testosterone compared to exogenous formulas. But unlike adrenal gland, clomiphene citrate preserves -- and potentially enriches -- sperm production. That makes drugs like clomiphene citrate one of only a few choices for men with low testosterone that wish to father children.
What kinds of testosterone-replacement therapy are available? *
The oldest form is an injection, which we still use since it is inexpensive and because we reliably get good testosterone levels in almost everybody. The drawback is that a man needs to come in every few weeks to find a shot. A roller-coaster effect may also happen as blood testosterone levels peak and then return to baseline. [Watch"Exogenous vs. endogenous testosterone," above.]
Topical treatments help maintain a more uniform level of blood testosterone. The first kind of topical treatment was a patch, but it has a very large rate of skin irritation. In 1 study, as many as 40% of men who used the patch developed a reddish area in their skin. That limits its use.
The most widely used testosterone preparation from the United States -- and the one I start almost everyone off -- is a topical gel. Based on my experience, it has a tendency to be consumed to good levels in about 80% to 85 percent of men, but leaves a substantial number who don't consume enough for it to have a favorable impact. [For specifics on various formulations, see table ]
Are there any drawbacks to using dyes? How long does it require them to get the job done?
Men who start using the implants need to return in to have their testosterone levels measured again to be certain they're absorbing the proper 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 blood actually goes up quite fast, within several doses. I normally measure it after two weeks, even though symptoms may not alter for a month or two.