A Harvard Specialist shares his thoughts on testosterone-replacement therapy
It might be said that testosterone is the thing that makes men, guys. It gives them their characteristic deep voices, big muscles, and facial and body hair, differentiating them from girls. It stimulates the growth of the genitals at puberty, plays a role in sperm production, fuels libido, and leads to normal erections. It also fosters the production of red blood cells, boosts mood, and assists cognition.
As time passes, the testicular"machinery" that makes testosterone slowly becomes less powerful, and testosterone levels start to drop, by approximately 1 percent a year, starting in the 40s. As men get into their 50s, 60s, and beyond, they might begin to have symptoms and signs of low testosterone like lower sex drive and sense of energy, erectile dysfunction, diminished energy, decreased muscle mass and bone density, and anemia. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" meaning low functioning and"gonadism" speaking to the testicles). Researchers estimate that the illness affects anywhere from two to six million men in the United States. Yet it is an underdiagnosed problem, with only about 5% of those affected receiving treatment.
Studies have revealed that testosterone-replacement therapy may provide a wide range of benefits for men with hypogonadism, including improved libido, mood, cognition, muscle mass, bone density, and red blood cell production. 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.
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 sexual and reproductive difficulties. He has developed specific expertise in treating low 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 treatment and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt the typical person to find a physician?
As a urologist, I have a tendency to see guys because they have sexual complaints. The primary hallmark of reduced testosterone is low sexual libido or desire, but another may be erectile dysfunction, and any guy who complains of erectile dysfunction should possess his testosterone level checked. Men can experience other symptoms, like more trouble achieving an orgasm, less-intense orgasms, a much smaller quantity of fluid from ejaculation, and a feeling of numbness in the manhood when they see or experience something that would normally be arousing.
The more of the symptoms there are, the more likely it is that a man has low testosterone. Many physicians often dismiss those"soft symptoms" as a normal part of aging, but they're often treatable and reversible by decreasing testosterone levels.
Are not those the very same symptoms that men have when they are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are quite a few medications that may reduce libido, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs can also reduce the amount of the ejaculatory fluid, no wonder. However a reduction in orgasm intensity normally doesn't 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 interest, it is more of a struggle to have a good erection.
How can you decide if or not a man is a candidate for testosterone-replacement therapy?
There are two ways that we determine whether somebody 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. Normally guys with the lowest testosterone have the most symptoms and men with highest testosterone possess the least. But there are a number of men who have reduced levels of testosterone in their blood and have no symptoms.
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 is a sensible guide. However, no one really agrees on a few. It is not like 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 clear.
| *Notice: The Endocrine Society publishes clinical practice guidelines see here with recommendations for who should and should not receive testosterone therapy. See"Endocrine Society recommendations summarized." Is complete testosterone the right point to be measuring? Or if we are measuring something else? Well, this is another area of confusion and great discussion, but I do not think that it's as confusing as it appears to be from the literature. When most physicians learned about testosterone in medical school, they learned about overall testosterone, or all the testosterone in the human body. But about half of the testosterone that's circulating in the bloodstream isn't available to cells. The available part of overall testosterone is called free testosterone, and it is readily available to the cells. Nearly every lab has a blood test to measure free testosterone. Though it's just a small fraction of this total, the free testosterone level is a fairly good indicator of low testosterone. It's not ideal, but the correlation is greater than with testosterone. This professional organization recommends testosterone therapy for men who have
Therapy Isn't recommended for men who've
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Do time of day, diet, or other elements influence testosterone levels?
For years, the recommendation was to receive a testosterone value early in the morning since levels begin to drop after 10 or even 11 a.m.. But the information behind that recommendation were attracted to healthy young men. Two recent studies demonstrated little change in blood glucose levels in men 40 and older within 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 percent, a modest amount, and probably insufficient to influence identification. Most guidelines still say it is important to do the evaluation in the morning, but for men 40 and over, it likely does not matter much, provided that they get their blood drawn before 6 or 5 p.m.
There are some very interesting findings about diet. By way of example, it seems 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 recommendations that are clear.
Exogenous vs. endogenous testosteroneWithin the following guide, testosterone-replacement treatment refers to the treatment of hypogonadism with adrenal gland -- testosterone that's manufactured outside the body. Depending on the formulation, treatment can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, reduced sperm count, increased red blood cell count, along with other side effects. Preliminary studies have proven that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, may foster the production of natural testosterone, also known as nitric oxide, in men. At a recent prospective study, 36 hypogonadal men took a daily dose of clomiphene citrate for at least three months. Within four to six weeks, all the guys had increased levels of testosteronenone reported any side effects during 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 (including the probability of developing prostate cancer) or whether it is more effective at boosting testosterone compared to exogenous formulas. But unlike exogenous testosterone, clomiphene citrate preserves -- and possibly enriches -- sperm production. That makes drugs such as clomiphene citrate one of only a few options for men with low testosterone that want to father children. What kinds of testosterone-replacement treatment are available? * The oldest form is an injection, which we use since it's cheap and because we faithfully become fantastic testosterone levels in almost everybody. The disadvantage is that a person should come in every few weeks to get a shot. A roller-coaster effect may also happen as blood glucose levels peak and then return to research. [See"Exogenous vs. endogenous testosterone," above.] Topical therapies help preserve a more uniform amount of blood testosterone. The first form of topical therapy has been a patch, but it has a quite large rate of skin irritation. In 1 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 in the United States -- and the one I start almost everyone off with -- is a topical gel. Based on my experience, it has a tendency to be absorbed to great levels in about 80% to 85 percent of men, but leaves a significant number who don't consume enough for this to have a positive effect. [For specifics on several different formulations, see table ] Are there any downsides to using gels? How long does it require them to get the job done? Men who begin using the gels have to come back in to have their own testosterone levels measured again to make certain they're absorbing the proper quantity. Our goal is that the mid to upper range of normal, which usually means around 500 to 600 ng/dl. The concentration of testosterone in the blood actually goes up quite quickly, in just a few doses. I normally measure it after 2 weeks, though symptoms may not alter for a month or two. |