A Harvard Specialist shares his thoughts on testosterone-replacement therapy
An interview with Abraham Morgentaler, M.D.
It could be said that testosterone is the thing that makes guys, men. It gives them their characteristic deep voices, large 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 regular erections. It also fosters the creation of red blood cells, boosts mood, and assists cognition.
Over time, the "machinery" which produces testosterone gradually becomes less effective, and testosterone levels begin to fall, by about 1 percent per year, beginning in the 40s. As guys get into their 50s, 60s, and beyond, they may begin to have symptoms and signs of low testosterone such as reduced libido and sense of vitality, erectile dysfunction, diminished energy, decreased muscle mass and bone density, and anemia. Taken together, these symptoms and signs are often called hypogonadism ("hypo" meaning low working and"gonadism" referring to the testicles). Researchers estimate that the condition affects anywhere from two to six million men in the United States. Yet it's an underdiagnosed problem, with just about 5 percent of those affected undergoing therapy.
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 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 ailments and male sexual and reproductive problems. He has developed specific experience 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 believes experts should reconsider the possible connection between testosterone-replacement therapy and prostate cancer.
Symptoms go to this siteread what he said and diagnosisWhat symptoms and signs of low testosterone prompt that the average person to see a physician?
As a urologist, I tend to observe men since they have sexual complaints. The primary hallmark of reduced testosterone is low sexual libido or desire, but another can be erectile dysfunction, and some other guy who complains of erectile dysfunction must possess his testosterone level checked. Men may experience different symptoms, such as more trouble achieving an orgasm, less-intense orgasms, a lesser amount of fluid out of ejaculation, and a feeling of numbness in the manhood when they see or experience something which would normally be arousing.
The more of the 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 are 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 precisely. There are a number of drugs which may reduce libido, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also reduce the quantity of the ejaculatory fluid, no question. But a decrease in orgasm intensity normally doesn't go along with treatment for BPH. Erectile dysfunction does not usually go together with it , though certainly if somebody has less sex drive or less interest, it is more of a struggle to have a good erection.
How do you determine whether or not a person is a candidate for testosterone-replacement treatment?
There are just two ways that 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 these two approaches is far from ideal. Normally men with the lowest testosterone have the most symptoms and men with highest testosterone have the least. But there are some men who have reduced levels of testosterone in their blood and have no signs.
Looking at the biochemical numbers, The Endocrine Society* considers low testosterone to be a total testosterone level of less than 300 ng/dl, and I think that's a reasonable guide. But no one quite agrees on a number. It's similar to diabetes, in which if your fasting sugar is over a certain level, they will say,"Okay, you've got it." With testosterone, that break point isn't quite as apparent.
| *Notice: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and should not receive testosterone treatment. |
Is total testosterone the right thing to be measuring? Or should we be measuring something else?
Well, this is just another area of confusion and great debate, but I don't think 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. However, about half of their testosterone that is circulating in the blood isn't readily available to 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 called free testosterone, and it's readily available to the cells. Even though it's only a small fraction of the total, the free testosterone level is a pretty good indicator of reduced testosterone. It is not ideal, but the significance is greater compared to testosterone.
Endocrine Society recommendations outlinedThis professional organization recommends testosterone therapy for men who have both
Therapy is not recommended for men who've
|
Do time daily, diet, or other elements influence testosterone levels?
For many years, the recommendation has been to get a testosterone value early in the morning since levels begin to drop after 10 or 11 a.m.. But the information behind this 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 the day. One reported no change in average testosterone till after 2 p.m. Between 6 and 2 p.m., it went down by 13%, a small amount, and probably not enough to affect diagnosis. Most guidelines nevertheless say it is important to do the evaluation in the morning, but for men 40 and over, it probably does not matter much, provided that they get their blood drawn before 6 or 5 p.m.
There are some rather 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 has not been studied thoroughly enough to create any clear recommendations.
Exogenous vs. endogenous testosteroneWithin this guide, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that is produced outside the body. Depending upon the formulation, therapy can cause skin irritation, breast tenderness and enlargement, sleep apnea, acne, reduced sperm count, increased red blood cell count, along with additional side effects. Within four to six months, all the men had increased levels of testosterone; none reported some side effects throughout the year they had been followed. Because clomiphene citrate is not accepted by the FDA for use in men, little information exists about the long-term ramifications of taking it (including the probability of developing prostate cancer) or whether it is more capable of boosting testosterone than exogenous formulations. But unlike adrenal gland, clomiphene citrate preserves -- and possibly enriches -- sperm production. That makes drugs such as clomiphene citrate one of only a few choices for men with low testosterone that wish to father children. |
What kinds of testosterone-replacement therapy are available? *
The earliest form is the injection, which we still use because it is cheap and because we reliably become fantastic testosterone levels in almost everybody. The disadvantage is that a man should come in every couple of weeks to get a shot. A roller-coaster effect can also occur as blood glucose levels peak and return to research. [Watch"Exogenous vs. endogenous testosterone," above.]
Topical treatments help maintain a more uniform level of blood testosterone. The first kind of topical treatment has been a patch, but it has a very high rate of skin irritation. In one study, as many as 40% of people that used the patch developed a reddish area in their skin. That limits 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. The gel comes from miniature tubes or in a special dispenser, and you rub it on your shoulders or upper arms once a day. Based on my experience, it tends to be absorbed to good degrees in about 80% to 85 percent of guys, but leaves a substantial number who don't absorb enough for it to have a positive effect. [For specifics on various formulations, see table below.]
Are there any downsides to using dyes? 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're absorbing the right 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.