A Harvard expert shares his thoughts on testosterone-replacement Treatment
An interview with Abraham Morgentaler, M.D.
It could be said that testosterone is the thing that makes guys, 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 normal erections. It also fosters the production of red blood cells, boosts mood, and aids cognition.
Over time, the testicular"machinery" that makes testosterone gradually becomes less effective, and testosterone levels start to fall, by about 1% per year, starting in the 40s. As guys get in their 50s, 60s, and beyond, they might begin to have symptoms and signs of low testosterone like reduced libido and sense of energy, erectile dysfunction, diminished energy, decreased muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" meaning low functioning 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 is an underdiagnosed problem, with just about 5 percent of these affected undergoing therapy.
But little consensus exists on 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 may stimulate prostate cancer.
He has developed specific expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he utilizes his patients, and why he believes experts should reconsider the potential connection between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt the typical person to see a doctor?
As a urologist, I have a tendency to observe men since they have sexual complaints. The main hallmark of reduced testosterone is low sexual desire or libido, but another can be erectile dysfunction, and some other guy who complains of erectile dysfunction should get his testosterone level checked. Men can experience other symptoms, such as more trouble achieving an orgasm, less-intense climaxes, a smaller quantity of fluid from ejaculation, and a feeling of numbness in the manhood when they see or experience something that 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 those"soft symptoms" as a normal part of aging, however, they are often treatable and reversible by decreasing testosterone levels.
Aren't those the very same symptoms that guys have when they're treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are a number of medications that may lessen sex drive, such as the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the quantity of the ejaculatory fluid, no question. However a decrease in orgasm intensity normally does not go together with treatment for BPH. Erectile dysfunction does not ordinarily go along with it either, though surely if somebody has less sex drive or less attention, it's more of a struggle to get a fantastic erection.
How do you decide whether or not a man is a candidate for testosterone-replacement treatment?
There are two ways 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 these two methods is far from ideal. Generally guys with the lowest testosterone have the most symptoms and men with maximum testosterone possess the least. However, there are some guys who have low levels of testosterone in their blood and have no signs.
Looking purely at the biochemical amounts, The Endocrine Society* considers low testosterone to be a entire testosterone level of less than 300 ng/dl, and I think that is a sensible guide. But no one really agrees on a few. It's 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 apparent.
| *Notice: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and should not receive testosterone therapy. Discover MoreDiscover More For a complete copy of the instructions, log these details on to www.endo-society.org. |
Is complete testosterone the right thing to be measuring? Or if we are measuring something else?
Well, this is just another area of confusion and great discussion, but I don't think that it's as confusing as it appears to be in the literature. When most physicians learned about testosterone in medical school, they learned about overall testosterone, or all of the testosterone in the body. But about half of their testosterone that is circulating in the bloodstream isn't available to the cells. It is tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG.
The available part of overall testosterone is called free testosterone, and it's readily available to cells. Almost every laboratory has a blood test to measure free testosterone. Even though it's only a little portion of the total, the free testosterone level is a pretty good indicator of reduced testosterone. It is not perfect, but the significance is greater than with total testosterone.
This professional organization recommends testosterone therapy for men who have
- Low levels of testosterone in the blood (less than 300 ng/dl)
- symptoms of low testosterone.
Therapy is not recommended for men who have
- Breast or prostate cancer
- a nodule on the prostate that can be felt during a DRE
- that a PSA higher than 3 ng/ml without additional evaluation
- a hematocrit greater than 50% or thick, viscous blood
- untreated obstructive sleep apnea
- severe lower urinary tract symptoms
- class III or IV heart failure.
Do time daily, diet, or other factors affect testosterone levels?
For years, the recommendation has been to receive a testosterone value early in the morning since levels begin to fall after 10 or even 11 a.m.. However, the information behind this recommendation were attracted to healthy young men. Two recent studies showed little change in blood testosterone levels in men 40 and older within the course of this day. One reported no change in typical testosterone till after 2 Between 2 and 6 p.m., it went down by 13%, a modest amount, and probably not enough to affect identification. Most guidelines nevertheless say it is important to perform the evaluation in the morning, however for men 40 and over, it probably doesn't matter much, as long as they get their blood drawn before 5 or 6 p.m.
There are some very interesting findings about diet. For instance, it appears that individuals that have a diet low in protein have lower testosterone levels than males who eat more protein. But diet has not been studied thoroughly enough to make any recommendations that are clear.
Exogenous vs. endogenous testosterone
Within this guide, testosterone-replacement treatment refers to the treatment of hypogonadism with adrenal gland -- testosterone that's produced outside the body. Based upon the formula, therapy can lead to skin irritation, breast tenderness and enlargement, sleep apnea, acne, decreased sperm count, increased red blood cell count, along with additional side effects.
Within four to six weeks, all the men had increased levels of testosteronenone reported any side effects throughout the entire 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 effects of carrying it (such as the risk of developing prostate cancer) or whether it's more effective at boosting testosterone than exogenous formulas. But unlike adrenal gland, clomiphene citrate preserves -- and possibly enriches -- sperm production. This makes drugs such as clomiphene citrate one of only a few options for men with low testosterone who want to father children.
What kinds of testosterone-replacement therapy can be found? *
The oldest form is the injection, which we still use because it is inexpensive and since we reliably become good testosterone levels in nearly everybody. The drawback is that a man should come in every few weeks to get a shot. A roller-coaster effect may also occur as blood testosterone levels peak and return to research. [See"Exogenous vs. endogenous testosterone," above.]
Topical treatments help maintain a more uniform amount of blood testosterone. The first kind of topical therapy has been a patch, but it has a very large rate of skin irritation. In one study, as many as 40 percent of men who used the patch developed a reddish area on their skin. That restricts its use.
The most widely used testosterone preparation in the United States -- and also the one I begin almost everyone off with -- is a topical gel. Based on my experience, it has a tendency to be absorbed to great levels in about 80% to 85 percent of men, but leaves a substantial number who do not absorb sufficient for this to have a favorable effect. [For specifics on several different formulations, see table below.]
Are there any downsides to using gels? How long does it require 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 goal is that the mid to upper assortment of normal, which usually means approximately 500 to 600 ng/dl. The concentration of testosterone in blood really goes up quite quickly, within several doses. I usually measure it after two weeks, even though symptoms may not change for a month or two.