A Harvard expert shares his Ideas on testosterone-replacement Treatment
It could be said that testosterone is the thing that makes men, 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 leads to normal erections. It also boosts the production of red blood cells, boosts mood, and aids cognition.
Over time, the testicular"machinery" which makes testosterone slowly becomes less effective, and testosterone levels start to drop, by about 1 percent per year, beginning in the 40s. As guys get in their 50s, 60s, and beyond, they may begin to have signs and symptoms of low testosterone like reduced sex drive and sense of energy, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often called hypogonadism ("hypo" significance low working and"gonadism" referring to the testicles). Yet it is an underdiagnosed problem, with just about 5 percent of those affected undergoing therapy.
Various studies have shown that testosterone-replacement therapy can provide a wide range of advantages for men with hypogonadism, such as 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 risks patients face. Much of the current debate focuses on the long-held belief that testosterone can stimulate prostate cancer.
He's 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 thinks specialists should rethink the possible link between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt that the typical person to see a doctor?
As a urologist, I tend to observe guys since they have sexual complaints. The main hallmark of low testosterone is low sexual libido or desire, but another may be erectile dysfunction, and some other guy who complains of erectile dysfunction should get his testosterone level checked. Men may experience different symptoms, like more trouble achieving an orgasm, less-intense climaxes, a much smaller amount of fluid from ejaculation, and a feeling of numbness in the penis when they see or experience something that would normally be arousing.
The more of these symptoms you will find, the more probable it is that a man has low testosterone. Many physicians often discount those"soft symptoms" as a normal part of aging, however, they're often treatable and reversible by decreasing testosterone levels.
Are not those the very same symptoms that men have when they're treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are a number of drugs that may lessen sex drive, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the amount of the ejaculatory fluid, no wonder. However a decrease in orgasm intensity normally doesn't go along with treatment for BPH. Erectile dysfunction does not usually go along with it either, though certainly if a person has less sex drive or less attention, it is more of a struggle to have a good erection.
How do you determine whether a man is a candidate for testosterone-replacement treatment?
There are just two ways we determine whether somebody has reduced testosterone. One is a blood test and the other one 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 possess 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* considers low testosterone to be a total testosterone level of less than 300 ng/dl, and I believe that is a sensible guide. But no one quite agrees on a number. It is similar to diabetes, where if your fasting glucose is over a certain level, they will 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. For a complete copy of the instructions, log on browse around here to www.endo-society.org. Is total testosterone the ideal thing to be measuring? Or should we be measuring something different? This is another area of confusion and good discussion, but I don't think it's as confusing as it is apparently from the literature. When most physicians 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 cells. It's closely 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. Though it's just a small portion of the overall, the free testosterone level is a pretty good indicator of reduced testosterone. It's not ideal, but the significance is greater than with testosterone. This professional organization urges testosterone therapy for men who have both Therapy Isn't recommended for men who've
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Do time daily, diet, or other factors influence testosterone levels?
For years, the recommendation was to receive a testosterone value early in the morning because levels begin to drop after 10 or even 11 a.m.. However, the data behind this recommendation were drawn from healthy young men. Two recent studies demonstrated little change in blood testosterone levels in men 40 and older within the course of the day. One reported no change in typical testosterone until after 2 Between 6 and 2 p.m., it went down by 13 percent, a modest sum, and probably not enough to affect identification. Most guidelines still say it is important to do the evaluation in the morning, however for men 40 and above, it likely does not 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 example, 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 researched thoroughly enough to create any clear recommendations.
Exogenous vs. endogenous testosteroneIn the following guide, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that's manufactured outside the body. Depending on the formula, therapy can lead to skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, along with additional 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, each one the guys had increased levels of testosteronenone reported some side effects throughout the entire year they were followed. Because clomiphene citrate is not approved by the FDA for use in males, little information exists regarding the long-term ramifications of carrying it (including the risk of developing prostate cancer) or whether it is more effective at boosting testosterone compared to exogenous formulas. But unlike adrenal gland, clomiphene citrate preserves -- and possibly enhances -- sperm production. That makes drugs such as clomiphene citrate one of just a few options for men with low testosterone that wish to father children. What forms of testosterone-replacement therapy can be found? * The earliest form is an injection, which we still use because it's inexpensive and because we faithfully become fantastic testosterone levels in almost everybody. The drawback is that a man needs to come in every few weeks to find a shot. A roller-coaster effect may also happen as blood glucose levels peak and then return to baseline. [See"Exogenous vs. endogenous testosterone," above.] Topical therapies help preserve a more uniform amount of blood glucose. The first form of topical therapy was a patch, but it has a very large rate of skin irritation. In 1 study, as many as 40 percent of men who used the patch developed a red area in their skin. That restricts its usage. The most commonly used testosterone preparation in the United States -- and also the one I begin almost everyone off with -- is a topical gel. There are two brands: AndroGel and Testim. Based on my experience, it tends to be consumed to great levels in about 80% to 85% of guys, but leaves a substantial number who do not consume enough for this to have a positive impact. [For details on various formulations, see table ] Are there any drawbacks to using gels? How much time does it take for them to work? Men who begin using the implants need to come back in to have their testosterone levels measured again to be sure they're absorbing the proper amount. Our target is that the mid to upper range of normal, which generally means around 500 to 600 ng/dl. The concentration of testosterone in the blood really goes up quite quickly, within several doses. I usually measure it after 2 weeks, though symptoms may not alter for a month or two. |