A Harvard expert shares his Ideas on testosterone-replacement Treatment
It might be said that testosterone is what makes men, guys. It gives them their characteristic deep voices, big 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 creation of red blood cells, boosts mood, and assists cognition.
Over time, the testicular"machinery" which makes testosterone gradually becomes less powerful, and testosterone levels start to fall, by approximately 1% a year, starting in the 40s. As men get into their 50s, 60s, and beyond, they might start to have signs and symptoms of low testosterone like lower sex drive and sense of energy, erectile dysfunction, decreased 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" speaking to the testicles). Researchers estimate that the illness affects anywhere from two to six million men in the United States. Yet it's an underdiagnosed issue, with only about 5 percent of those affected receiving treatment.
Various studies have shown that testosterone-replacement therapy may provide a wide range of advantages for men with hypogonadism, including improved libido, mood, cognition, muscle mass, bone density, and red blood cell production. But little consensus exists about 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 reproductive and sexual difficulties. 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 own patients, and he thinks experts should reconsider the potential link between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt that the typical man to find a doctor?
As a urologist, I have a tendency 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 any man who complains of erectile dysfunction must get his testosterone level checked. Men can experience other symptoms, like more trouble achieving an orgasm, less-intense orgasms, a lesser amount of fluid from ejaculation, and a sense of numbness in the penis when they see or experience something that would usually be arousing.
The more of these symptoms there are, the more probable it is that a man has low testosterone. Many physicians often dismiss these"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 that 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 decrease in orgasm intensity normally does not go along with therapy for BPH. Erectile dysfunction does not ordinarily go together with it either, though certainly if somebody has less sex drive or less attention, it is more of a challenge to get a fantastic erection.
How can you determine whether or not a person is a candidate for testosterone-replacement therapy?
There are two ways that we determine whether someone has reduced testosterone. One is a blood test and the other is by characteristic symptoms and signs, and the correlation between these two approaches is far from ideal. Generally men with the lowest testosterone have the most symptoms and guys with maximum testosterone have the least. However, there are a number of guys who have low levels of testosterone in their blood and have no symptoms.
Looking purely at the biochemical numbers, The Endocrine Society* believes low testosterone for a entire 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's not like diabetes, in which if your fasting sugar is over a certain level, they'll say,"Okay, you've got it." With testosterone, that break point is not quite as clear.
| *Note: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and should not receive testosterone treatment. See"Endocrine Society useful link recommendations summarized." For a complete copy go to this web-site of the guidelines, log on to www.endo-society.org. Is total testosterone the right thing to be measuring? Or should we be measuring something else? Well, this is another area of confusion and great debate, but I don't think that it's as confusing as it is apparently from the literature. When most doctors learned about testosterone in medical school, they learned about total testosterone, or all the testosterone in the body. But about half of the testosterone that's circulating in the bloodstream is not available to the cells. It's tightly bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG. The biologically available part of total testosterone is known as free testosterone, and it is readily available to cells. Even though it's just a little portion of this overall, the free testosterone level is a fairly good indicator of reduced testosterone. It's not perfect, but the correlation is greater than with total testosterone.
Do time of day, 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 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 until after 2 Between 2 and 6 p.m., it went down by 13 percent, a modest sum, and probably not enough to influence identification. Most guidelines still say it is important to perform the test in the morning, however for men 40 and above, it probably does not matter much, as long as they obtain their blood drawn before 5 or 6 p.m. There are a number of rather interesting findings about diet. By way of example, it seems that those 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 this article, testosterone-replacement treatment refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that is produced outside the body. Depending upon the formula, treatment can cause skin irritation, breast tenderness and enlargement, sleep apnea, acne, reduced sperm count, increased red blood cell count, along with 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 months, all the guys had increased levels of testosterone; none reported some side effects during the entire year they had been followed. Since clomiphene citrate isn't approved by the FDA for use in males, little information exists about the long-term effects of carrying it (including the probability of developing prostate cancer) or if it is more capable of boosting testosterone compared to exogenous formulations. But unlike adrenal gland, clomiphene citrate preserves -- and potentially enriches -- sperm production. That makes medication like clomiphene citrate one of just a few options for men with low testosterone who want to father children. What kinds of testosterone-replacement therapy are available? * The earliest form is an injection, which we use since it is cheap and since we faithfully get good testosterone levels in nearly everybody. The drawback is that a person should come in every few weeks to get a shot. A roller-coaster effect can also occur as blood testosterone levels peak and return to baseline. [Watch"Exogenous vs. endogenous testosterone," above.] Topical treatments help preserve a more uniform level 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 people that used the patch developed a reddish area on their skin. That limits its use. The most commonly used testosterone preparation in the United States -- and the one I begin almost everyone off -- is a topical gel. There are two brands: AndroGel and Testim. Based on my experience, it tends to be absorbed to good levels in about 80% to 85% of men, but that leaves a significant number who do not consume sufficient for this to have a favorable impact. [For details 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 come back in to have their testosterone levels measured again to make sure they are absorbing the proper amount. Our target is 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, within several doses. I normally measure it after 2 weeks, even although symptoms may not alter for a month or two. |