A Harvard Specialist shares his thoughts on testosterone-replacement therapy
It could be stated that testosterone is the thing that makes guys, 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. Additionally, it fosters the creation of red blood cells, boosts mood, and aids cognition.
As time passes, the testicular"machinery" which produces testosterone gradually becomes less powerful, and testosterone levels start to fall, by about 1% a year, beginning in the 40s. As men 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, decreased muscle mass and bone density, and nausea. Taken together, these signs and symptoms 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's an underdiagnosed problem, with only about 5% of those affected undergoing therapy.
Studies have shown that testosterone-replacement therapy may provide a vast range of advantages for men with hypogonadism, including enhanced libido, mood, cognition, muscle mass, bone density, and red blood cell production. Much of the current debate focuses on the long-held belief that testosterone may 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 difficulties. He has developed specific expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he utilizes his own patients, and why he believes specialists should rethink the potential connection between testosterone-replacement therapy and prostate cancer.
Symptoms and Source diagnosisWhat signs and symptoms of low testosterone prompt that the typical man to see a physician?
As a urologist, I tend to observe men since they have sexual complaints. The main hallmark of reduced testosterone is reduced sexual libido or desire, 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, like more difficulty achieving an orgasm, less-intense orgasms, a smaller amount of fluid from ejaculation, and a feeling of numbness in the manhood when they see or experience something that would usually 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, but 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 quite a few medications which 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. But a reduction in orgasm intensity normally doesn't go together with therapy for BPH. Erectile dysfunction does not ordinarily go along with it , though surely if a person has less sex drive or less interest, it's more of a struggle to have a fantastic erection.
How can you determine whether a person is a candidate for testosterone-replacement therapy?
There are two ways 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 methods is far from perfect. Generally men with the lowest testosterone have the most symptoms and guys with maximum testosterone have the least. However, there are some guys who have low 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 total testosterone level of less than 300 ng/dl, and I think that's a sensible guide. However, no one really agrees on a number. It is not like diabetes, where if your fasting sugar is above a certain level, they will say,"Okay, you've got it." With testosterone, that break point isn't quite as apparent.
| *Notice: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and shouldn't receive testosterone treatment. Watch"Endocrine Society recommendations summarized." |
Is total testosterone the right point to be measuring? Or should we be measuring something else?
Well, this is just another area of confusion and good debate, but I don't think it's as confusing as it appears to be from the literature. When most doctors learned about testosterone in medical school, they learned about overall testosterone, or all of the testosterone in the body. However, about half of their testosterone that's circulating in the blood isn't available to the cells. It is tightly bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG.
The available portion of total testosterone is called free testosterone, and it is readily available to the cells. Almost every lab has a blood test to measure free testosterone. Though it's just a little fraction of this total, the free testosterone level is a pretty good indicator of reduced testosterone. It's not perfect, but the significance is greater than with total testosterone.
This professional organization urges testosterone treatment for men who have both
Therapy is not Suggested for men who have
- Prostate or breast cancer
- a nodule on the prostate which can be felt during a DRE
- a PSA higher than 3 ng/ml without additional evaluation
- a hematocrit greater than 50 percent 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 factors affect testosterone levels?
For years, the recommendation has been to get a testosterone value early in the morning since levels begin to fall after 10 or even 11 a.m.. But the information behind this 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 until after 2 p.m. Between 6 and 2 p.m., it went down by 13%, a small amount, and probably insufficient to influence identification. Most guidelines nevertheless say it is important to do the test in the morning, but for men 40 and above, it probably does not matter much, as long as they obtain their blood drawn before 6 or 5 p.m.
There are some rather interesting findings about dietary supplements. For instance, 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 create any clear recommendations.
Exogenous vs. endogenous testosteroneWithin 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, therapy can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, and other side effects. In a recent prospective study, 36 hypogonadal men took a daily dose of clomiphene citrate for at least three months. Within four to six weeks, each one of the men had heightened 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 carrying it (including the risk of developing prostate cancer) or whether it is more capable of boosting testosterone than exogenous formulas. But unlike exogenous testosterone, clomiphene citrate preserves -- and potentially enriches -- sperm production. This makes medication such as clomiphene citrate one of just a few options for men with low testosterone that want to father children. |
What forms of testosterone-replacement treatment are available? *
The oldest form is an injection, which we still use since it is inexpensive and since we faithfully get fantastic testosterone levels in almost everybody. The disadvantage is that a man needs to come in every few weeks to get a shot. A roller-coaster effect can also happen as blood testosterone levels peak and return to research.
Topical therapies 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 one study, as many as 40 percent of men who used the patch developed a red area on their skin. That limits its usage.
The most widely used testosterone preparation from the United States -- and the one I start almost everyone off -- is a topical gel. There are just two brands: AndroGel and Testim. Based on my experience, it has a tendency to be absorbed to great degrees in about 80% to 85 percent of guys, but that leaves a significant number who do not absorb enough for it to have a favorable effect. [For specifics on several different formulations, see table ]
Are there any drawbacks to using dyes? How much time does it take for them to work?
Men who start using the gels have to come back in to have their testosterone levels measured again to make certain they are absorbing the proper amount. Our goal is that the mid to upper assortment of normal, which generally means around 500 to 600 ng/dl. The concentration of testosterone in blood actually goes up quite quickly, in just a few doses. I usually measure it after two weeks, though symptoms may not change for a month or two.