A Harvard expert shares his thoughts on testosterone-replacement therapy
It could be stated that testosterone is what makes men, guys. It gives them their characteristic deep voices, large muscles, and body and facial hair, distinguishing them from women. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and contributes to normal erections. Additionally, it fosters the production of red blood cells, boosts mood, and aids cognition.
As time passes, the testicular"machinery" that makes testosterone gradually becomes less effective, and testosterone levels start to fall, by approximately 1% per year, beginning in the 40s. As men get in their 50s, 60s, and beyond, they might start to have signs and symptoms of low testosterone like reduced sex drive and sense of energy, erectile dysfunction, decreased energy, decreased muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often called hypogonadism ("hypo" significance low working and"gonadism" speaking to the testicles). Researchers estimate that the illness affects anywhere from two to six million men in the USA. Yet it's an underdiagnosed issue, with only about 5% of those affected undergoing therapy.
Studies have shown that testosterone-replacement therapy may offer a vast selection of benefits 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 may stimulate prostate cancer.
He has developed specific expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment strategies he uses with his 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 the typical man to find a physician?
As a urologist, I have a tendency to observe guys because they have sexual complaints. The main hallmark of low testosterone is reduced sexual desire or libido, but another can be erectile dysfunction, and some other guy who complains of erectile dysfunction must get his testosterone level checked. Men can experience other symptoms, such as more trouble achieving an orgasm, less-intense climaxes, a much smaller quantity of fluid from ejaculation, and a sense of numbness in the manhood when they see or experience something that would usually 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 dismiss these"soft symptoms" as a normal part of aging, but they are often treatable and reversible by normalizing testosterone levels.
Aren't those the very same symptoms that guys have when they are treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are quite a few drugs which may lessen sex drive, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the amount of the ejaculatory fluid, no wonder. But a reduction in orgasm intensity normally doesn't go along with therapy for BPH. Erectile dysfunction does not ordinarily go along with it either, though surely if somebody has less sex drive or less attention, it is more of a challenge to get a good erection.
How do you determine whether or not a man is a candidate for testosterone-replacement therapy?
There are two ways 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 those two methods is far from perfect. Normally guys with the lowest testosterone have the most symptoms and men with highest testosterone possess the least. However, there are some guys who have low levels of testosterone in their blood and have no symptoms.
Looking at the biochemical numbers, The Endocrine Society* believes low testosterone for a total testosterone level of less than 300 ng/dl, and I believe that is a sensible guide. However, no one quite agrees on a few. It is 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 isn't quite as clear.
| *Notice: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and shouldn't receive testosterone therapy. For visite site a complete copy of these click for more guidelines, log on to www.endo-society.org. Is total testosterone the right thing to be measuring? Or if we are measuring something else? This is another area of confusion and great debate, but I don't think that 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. But about half of their testosterone that is circulating in the blood is not available to cells. The biologically available part of overall testosterone is called free testosterone, and it is readily available to the cells. Though it's only a little fraction of the total, the free testosterone level is a pretty good indicator of low testosterone. It is not perfect, but the correlation is greater than with total testosterone.
Do time of day, diet, or other factors influence testosterone levels? For years, the recommendation was to get a testosterone value early in the morning since levels begin to fall after 10 or even 11 a.m.. However, the data behind that 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 till after 2 p.m. Between 2 and 6 p.m., it went down by 13 percent, a small amount, and probably not enough to affect identification. Most guidelines nevertheless say it's important to perform the test in the morning, but for men 40 and above, it probably doesn't matter much, provided that they obtain their blood drawn before 6 or 5 p.m. There are a number of rather interesting findings about diet. For example, it appears that individuals who have a diet low in protein have lower testosterone levels than males who consume more protein. But diet has not been studied thoroughly enough to create any recommendations that are clear. In the following article, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that's produced outside the body. Based upon the formulation, therapy can cause skin irritation, breast tenderness and enlargement, sleep apnea, acne, decreased sperm count, increased red blood cell count, along with other side effects. Preliminary research has proven that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, can boost the creation of natural testosterone, also known as endogenous testosterone, 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, each one of the guys had increased levels of testosterone; none reported some side effects throughout the entire year they were followed. Since clomiphene citrate isn't accepted by the FDA for use in men, 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 formulas. But unlike exogenous testosterone, clomiphene citrate maintains -- and potentially enriches -- sperm production. This makes drugs like clomiphene citrate one of just a few choices for men with low testosterone that want to father children. |
What forms of testosterone-replacement therapy are available? *
The earliest form is the injection, which we still use because it's cheap and because we faithfully become good testosterone levels in nearly everybody. The disadvantage is that a person needs to come in every few weeks to find a shot. A roller-coaster effect may also occur as blood testosterone levels peak and then return to baseline.
Topical treatments help maintain a more uniform level of blood testosterone. The first form of topical therapy was a patch, but it has a quite large rate of skin irritation. In 1 study, as many as 40% of men who used the patch developed a red area in their skin. That limits its usage.
The most widely used testosterone preparation from the United States -- and the one I start almost everyone off -- is a topical gel. There are just two brands: AndroGel and Testim. The gel comes from tiny tubes or within a special dispenser, and you rub it on your shoulders or upper arms once a day. Based on my experience, it has a tendency to be absorbed to great levels in about 80% to 85% of men, but that leaves a significant number who don't absorb sufficient for it to have a positive impact. [For specifics on various formulations, see table ]
Are there any downsides to using dyes? How much time does it require them to work?
Men who begin using the implants need to return in to have their testosterone levels measured again to make sure they are absorbing the right amount. Our target is the mid to upper assortment of normal, which generally 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 usually measure it after two weeks, although symptoms may not change for a month or two.