A Harvard expert shares his thoughts on testosterone-replacement Treatment
It might be said that testosterone is what makes men, guys. It gives them their characteristic deep voices, large muscles, and facial and body hair, distinguishing them from girls. It stimulates the development of the genitals at puberty, plays a role in sperm production, fuels libido, and contributes to regular erections. Additionally, it fosters the production of red blood cells, boosts mood, and assists cognition.
Over time, the testicular"machinery" which produces testosterone gradually becomes less powerful, and testosterone levels begin to fall, by approximately 1 percent per year, beginning in the 40s. As guys get in their 50s, 60s, and beyond, they may begin 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 anemia. Taken together, these signs and symptoms are often referred to as hypogonadism ("hypo" meaning low functioning and"gonadism" speaking 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 just about 5% of those 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 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 sexual and reproductive problems. He's developed specific expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment plans he uses with his patients, and why he thinks specialists should rethink the possible connection between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt the typical man to find a doctor?
As a urologist, I tend to observe men since they have sexual complaints. The primary hallmark of low testosterone is reduced 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 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'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 quite a few drugs which may reduce libido, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the amount of the ejaculatory fluid, no question. But a reduction in orgasm intensity usually doesn't go together with therapy for BPH. Erectile dysfunction does not usually go along with it either, though surely if a person has less sex drive or less attention, it is more of a challenge to get a good erection.
How can you decide if or not a man is a candidate for testosterone-replacement treatment?
There are just two ways that we determine whether somebody has low testosterone. One is a blood test and the other is by characteristic signs and symptoms, and the correlation between these two approaches is far from ideal. Generally men with the lowest testosterone have the most symptoms and men with highest testosterone have the least. But there are some men who have low levels of testosterone in their blood and have no signs.
Looking at the biochemical numbers, The Endocrine Society* considers low testosterone to be a total testosterone level of less than 300 ng/dl, and I think that's a reasonable guide. But no one quite agrees on a number. It's not like diabetes, where if your fasting glucose is above a certain level, they'll say,"Okay, you've got it." With testosterone, that break point isn't quite as clear.
| *Notice: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and should not receive testosterone treatment. Watch"Endocrine Society click this site recommendations site summarized." For a complete copy of these instructions, log on to www.endo-society.org. Is total testosterone the right thing to be measuring? Or should we be measuring something else? This is just another area of confusion and good discussion, but I do not think it's as confusing as it appears to be in the literature. When most doctors learned about testosterone in medical school, they learned about overall testosterone, or all of the testosterone in the human body. However, about half of the testosterone that's circulating in the bloodstream is not available to cells. It's tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG. The available portion of overall testosterone is known as free testosterone, and it's readily available to the cells. Though it's just a small fraction of the overall, the free testosterone level is a fairly good indicator of low testosterone. It's not ideal, but the significance is greater compared to total testosterone.
Do time daily, diet, or other elements affect testosterone levels? For years, the recommendation was to get a testosterone value early in the morning because levels begin to drop after 10 or 11 a.m.. However, the data behind this recommendation were attracted to healthy young men. Two recent studies showed little change in blood glucose levels in men 40 and older over the course of this day. One reported no change in average testosterone till after 2 Between 6 and 2 p.m., it went down by 13%, a small sum, and probably not enough to affect diagnosis. Most guidelines still say it is important to do the evaluation in the morning, however for men 40 and above, it likely doesn't matter much, provided that they obtain their blood drawn before 5 or 6 p.m. There are a number of very interesting findings about dietary supplements. For instance, it appears that individuals that have a diet low in protein have lower testosterone levels than men who eat more protein. But diet hasn't been researched thoroughly enough to create any clear recommendations. Within the following guide, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that is produced outside the body. Depending upon the formulation, treatment can lead to skin irritation, breast tenderness and enlargement, sleep apnea, acne, reduced sperm count, increased red blood cell count, along with other side effects. At 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 of the guys had increased levels of testosterone; none reported some side effects throughout the year they were followed. Since clomiphene citrate is not approved by the FDA for use in males, little information exists regarding the long-term effects of taking it (such as the risk of developing prostate cancer) or whether it's more capable of boosting testosterone than exogenous formulations. But unlike adrenal gland, clomiphene citrate maintains -- and possibly enhances -- sperm production. That makes medication such as clomiphene citrate one of only a few choices for men with low testosterone that wish to father children. |
What kinds of testosterone-replacement treatment can be found? *
The oldest form is an injection, which we still use since it is inexpensive and because we reliably become fantastic testosterone levels in almost everybody. The disadvantage is that a man needs to come in every couple of weeks to find a shot. A roller-coaster effect may also happen as blood testosterone levels peak and then return to baseline.
Topical treatments help preserve a more uniform amount of blood testosterone. The first form of topical therapy was a patch, but it has a very high rate of skin irritation. In 1 study, as many as 40 percent of people that used the patch developed a reddish area in their skin. That restricts its use.
The most commonly used testosterone preparation in the United States -- and the one I start almost everyone off with -- is a topical gel. There are just two brands: AndroGel and Testim. Based on my experience, it has a tendency to be consumed to great degrees in about 80% to 85 percent of guys, but leaves a substantial number who don't absorb enough for it to have a positive effect. [For specifics on various formulations, see table below.]
Are there any drawbacks to using gels? How long does it take for them to work?
Men who start using the gels have to return in to have their own testosterone levels measured again to be certain they are absorbing the proper amount. Our target is 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 quickly, within a few doses. I normally measure it after 2 weeks, even although symptoms may not change for a month or two.