A Harvard Specialist shares his thoughts on testosterone-replacement therapy
It might 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 assists cognition.
As time passes, the testicular"machinery" which produces testosterone slowly 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 begin 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 functioning and"gonadism" referring to the testicles). Yet it is an underdiagnosed problem, with only about 5% of those affected undergoing therapy.
Studies have shown that testosterone-replacement therapy may provide a vast selection of advantages for men with hypogonadism, including improved 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 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 diseases and male reproductive and sexual difficulties. He has 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 thinks experts should reconsider the possible link between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt that the average person to find 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 may be erectile dysfunction, and some other man who complains of erectile dysfunction should possess his testosterone level checked. Men may experience other symptoms, like more difficulty achieving an orgasm, less-intense climaxes, a much smaller quantity 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 the symptoms there are, the more probable it is that a man has low testosterone. Many physicians often dismiss 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 drugs which may reduce libido, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs may also decrease the quantity of the ejaculatory fluid, no question. However a reduction in orgasm intensity usually doesn't go along with therapy for BPH. Erectile dysfunction does not ordinarily go along with it , 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 determine if a person is a candidate for testosterone-replacement therapy?
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 guys 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 for a total testosterone level of less than 300 ng/dl, and I believe that's a sensible guide. But no one quite agrees on a few. It's similar to diabetes, in which if your fasting glucose is above 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 recommends clinical practice guidelines with recommendations for who should and shouldn't look at this site receive testosterone treatment. use this link For a complete copy of these guidelines, company website log on to www.endo-society.org. Is total testosterone the ideal thing to be measuring? Or if we are measuring something else? This is just another area of confusion and great discussion, but I don't think that it's as confusing as it appears to be in the literature. When most physicians learned about testosterone in medical school, they heard about total testosterone, or all of the testosterone in the body. But about half of their testosterone that is circulating in the bloodstream is not available to the cells. It is closely bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG. The biologically available part of overall testosterone is known as free testosterone, and it is readily available to cells. Though it's only a little fraction of this overall, the free testosterone level is a fairly good indicator of reduced testosterone. It is not perfect, but the correlation is greater than with total testosterone.
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 begin to drop after 10 or even 11 a.m.. But the data behind this recommendation were drawn from healthy young men. Two recent studies showed little change in blood glucose levels in men 40 and mature over the course of this day. One reported no change in average testosterone until after 2 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 evaluation in the morning, but for men 40 and over, it probably doesn't 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 males who eat more protein. But diet hasn't been researched thoroughly enough to make any recommendations that are clear. In the following guide, testosterone-replacement therapy refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that's produced outside the body. Depending on the formula, therapy can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, and additional side effects. Preliminary studies have shown that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, can boost the production of natural testosterone, known as nitric oxide, in men. In a recent prospective study, 36 hypogonadal men took a daily dose of clomiphene citrate for at least three months. Within four to six months, all the men had heightened levels of testosteronenone reported some side effects throughout the year they were followed. Since clomiphene citrate isn't approved by the FDA for use in men, little information exists regarding the long-term ramifications of taking it (such as the probability of developing prostate cancer) or whether it's more effective at boosting testosterone compared to exogenous formulations. But unlike exogenous testosterone, clomiphene citrate maintains -- and possibly enhances -- sperm production. This makes medication like clomiphene citrate one of just a few choices for men with low testosterone that want to father children. |
What kinds of testosterone-replacement therapy can be found? *
The oldest form is the injection, which we still use since it's cheap and because we faithfully get fantastic testosterone levels in nearly everybody. The drawback is that a man should come in every few weeks to get a shot. A roller-coaster effect may also occur as blood glucose levels peak and then 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 large rate of skin irritation. In one study, as many as 40 percent of men who used the patch developed a reddish area in their skin. That limits its usage.
The most commonly used testosterone preparation in the United States -- and also the one I start almost everyone off with -- is a topical gel. There are just two brands: AndroGel and Testim. According to my experience, it has a tendency to be absorbed to great degrees in about 80% to 85% of guys, but leaves a significant number who don't absorb sufficient for it to have a positive impact. [For details 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 gels have to return in to have their own testosterone levels measured again to make sure they are absorbing the proper amount. 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 actually goes up quite fast, in just several doses. I usually measure it after two weeks, although symptoms may not alter for a month or two.