A Harvard expert shares his thoughts on testosterone-replacement therapy
It could be stated that testosterone is what makes men, men. It gives them their characteristic deep voices, big muscles, and body and facial 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 regular erections. Additionally, it boosts the production of red blood cells, boosts mood, and aids cognition.
Over time, the testicular"machinery" which produces testosterone gradually becomes less effective, and testosterone levels begin to drop, by about 1% a year, starting in the 40s. As men get into their 50s, 60s, and beyond, they may start to have signs and symptoms of low testosterone such as lower sex drive and sense of vitality, erectile dysfunction, decreased energy, decreased muscle mass and bone density, and nausea. Taken together, these signs and symptoms are often called hypogonadism ("hypo" significance low functioning and"gonadism" referring 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 problem, with only about 5 percent of those affected undergoing therapy.
But little consensus exists about what constitutes low testosterone, when testosterone supplementation makes sense, or what risks patients face.
He's developed specific expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment plans he uses with his own patients, and why he thinks experts should reconsider the possible connection between testosterone-replacement treatment 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 have a tendency to observe guys because they have sexual complaints. The primary hallmark of low testosterone is low sexual desire or libido, but another may be erectile dysfunction, and some other guy who complains of erectile dysfunction should get his testosterone level checked. Men can experience other symptoms, like more difficulty achieving an orgasm, less-intense climaxes, a smaller amount of fluid from 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 there are, the more probable it is that a man has low testosterone. Many physicians tend to dismiss these"soft symptoms" as a normal part of aging, but they're often treatable and reversible by normalizing testosterone levels.
Are not 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 medications that may reduce libido, such as the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs can also reduce the quantity of the ejaculatory fluid, no question. However a reduction in orgasm intensity normally doesn't go along with therapy for BPH. Erectile dysfunction does not ordinarily go along with it , though surely if somebody has less sex drive or less interest, it is more of a challenge to have a good erection.
How do you decide whether a person is a candidate for testosterone-replacement therapy?
There are just two ways that we determine whether someone has low testosterone. One is a blood test and the other one is by characteristic symptoms and signs, and the correlation between those two methods is far from ideal. Generally men with the lowest testosterone have the most symptoms and guys with maximum testosterone possess the least. But 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* considers low testosterone for a total testosterone level of less than 300 ng/dl, and I think that is a reasonable guide. But no one quite agrees on a number. It's similar to diabetes, where if your fasting glucose is over a certain level, they'll say,"Okay, you've got it." With testosterone, that break point is not quite as apparent.
| *Note: The Endocrine Society recommends clinical practice guidelines with recommendations for who should you could try these out and shouldn't receive testosterone therapy. For article source 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? Well, this is another area of confusion and good discussion, 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 total testosterone, or all the testosterone in the human body. But about half of the testosterone that's circulating in the bloodstream is not available to cells. The biologically available part of total testosterone is called free testosterone, and it is readily available to the cells. Though it's just a small fraction of the total, the free testosterone level is a pretty good indicator of low testosterone. It is not ideal, but the correlation is greater than with testosterone. This professional organization urges testosterone treatment for men who have
Therapy Isn't recommended for men who've
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Do time of day, diet, or other elements affect testosterone levels?
For years, the recommendation has been to get a testosterone value early in the morning since levels start to fall after 10 or even 11 a.m.. But the information behind that recommendation were drawn from healthy young men. Two recent studies demonstrated little change in blood glucose levels in men 40 and mature within the course of this day. One reported no change in typical testosterone until after 2 p.m. Between 2 and 6 p.m., it went down by 13 percent, a modest amount, and probably not enough to influence identification. Most guidelines still say it's important to perform the evaluation in the morning, but for men 40 and over, it likely does not matter much, as long as they get their blood drawn before 5 or 6 p.m.
There are a number of rather interesting findings about diet. For instance, it appears that those 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 clear recommendations.
Exogenous vs. endogenous testosteroneIn this guide, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that is manufactured outside the body. Depending upon the formulation, treatment 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, may boost the creation of natural testosterone, known as endogenous testosterone, in men. Within four to six weeks, each one of the men had heightened levels of testosteronenone reported some side effects during the year they had been followed. Because clomiphene citrate is not approved by the FDA for use in men, little information exists about the long-term effects of taking it (including the probability of developing prostate cancer) or whether it is more capable of boosting testosterone compared to exogenous formulas. But unlike exogenous testosterone, clomiphene citrate maintains -- and potentially enriches -- sperm production. That makes drugs like clomiphene citrate one of only a few choices for men with low testosterone who wish to father children. |
What kinds of testosterone-replacement therapy are available? *
The oldest form is an injection, which we still use since it is cheap and since we faithfully become fantastic testosterone levels in almost everybody. The disadvantage is that a person should come in every couple of weeks to get a shot. A roller-coaster effect may also occur as blood testosterone levels peak and return to research.
Topical therapies help maintain a more uniform amount of blood glucose. The first kind of topical treatment was a patch, but it has a very large rate of skin irritation. In one study, as many as 40% of men who used the patch developed a red area in their skin. That restricts its use.
The most commonly used testosterone preparation from the United States -- and also the one I begin almost everyone off -- is a topical gel. According to my experience, it tends to be consumed to great degrees in about 80% to 85% of guys, but leaves a significant number who do not absorb enough for it to have a favorable effect. [For specifics on various formulations, see table below.]
Are there any downsides to using gels? How long does it take for them to work?
Men who begin using the gels have to come back in to have their testosterone levels measured again to be sure they are absorbing the right amount. Our target is the mid to upper assortment of normal, which usually means approximately 500 to 600 ng/dl. The concentration of testosterone in the blood really goes up quite fast, in just a few doses. I usually measure it after 2 weeks, even though symptoms may not alter for a month or two.