A Harvard expert shares his thoughts on testosterone-replacement therapy
An interview with Abraham Morgentaler, M.D.
It could be stated that testosterone is the thing that makes guys, men. It gives them their characteristic deep voices, large muscles, and body and facial hair, differentiating them from women. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and contributes to regular erections. It also fosters the creation of red blood cells, boosts mood, and assists cognition.
Over time, the testicular"machinery" which makes testosterone gradually becomes less powerful, and testosterone levels begin to fall, by approximately 1 percent a year, starting 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 lower libido 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). Researchers estimate that the condition affects anywhere from two to six million men in the USA. Yet it is an underdiagnosed issue, with only about 5 percent of those affected receiving treatment.
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.
He's developed particular experience in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment strategies he utilizes his own patients, and he thinks specialists should rethink the possible connection between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt the typical man to find a doctor?
As a urologist, I tend to observe men since they have sexual complaints. The primary hallmark of low testosterone is low sexual libido or desire, but another can be erectile dysfunction, and some other man who complains of erectile dysfunction should possess his testosterone level checked. Men may experience other symptoms, like more difficulty achieving an orgasm, less-intense orgasms, a much smaller quantity of fluid out of 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 you will find, the more likely it is that a man has low testosterone. Many physicians often discount these"soft symptoms" as a normal part of aging, however, they're often treatable and reversible by normalizing 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 quite a few drugs that may reduce libido, such as the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also reduce the quantity of the ejaculatory fluid, no wonder. But a decrease in orgasm intensity normally doesn't go along with treatment for BPH. Erectile dysfunction does not ordinarily go together with it , though certainly if a person has less sex drive or less attention, it is more of a struggle to get a good erection.
How can you decide if 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 these two approaches is far from ideal. Generally men with the lowest testosterone have the most symptoms and men with highest testosterone have the least. However, there are a number of guys who have reduced levels of testosterone in their blood and have no symptoms.
Looking purely at the biochemical amounts, The Endocrine Society* believes low testosterone for a entire 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's not like diabetes, where if your fasting glucose is above a certain level, they'll say,"Okay, you've got it." With testosterone, that break point is not quite as clear.
| *Note: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and shouldn't receive testosterone therapy. For a complete copy of Home Page these instructions, have a peek at these guys log on to www.endo-society.org. |
Is total testosterone the ideal point to be measuring? Or if we are measuring something different?
This is just another area of confusion and good discussion, 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 total testosterone, or all of the testosterone in the human body. However, about half of their testosterone that's circulating in the bloodstream is not available to the cells. It's closely bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG.
The available part of total testosterone is known as free testosterone, and it is readily available to cells. Almost every lab has a blood test to measure free testosterone. Even though it's only a little portion of this total, the free testosterone level is a pretty good indicator of low testosterone. It is not ideal, but the significance is greater than with total testosterone.
This professional organization recommends testosterone treatment for men who have
- Low levels of testosterone in the blood (less than 300 ng/dl)
- symptoms of low testosterone.
Therapy Isn't Suggested for men who have
- Prostate or breast cancer
- a nodule on the prostate that may be felt during a DRE
- that a PSA greater than 3 ng/ml without further analysis
- that 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 of day, diet, or other elements affect testosterone levels?
For years, the recommendation was to receive a testosterone value early in the morning because levels begin to drop after 10 or 11 a.m.. However, the data behind this recommendation were attracted to 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 modest sum, and probably not enough to influence identification. Most guidelines still say it is important to perform the test in the morning, however for men 40 and above, it likely doesn't matter much, provided that they get their blood drawn before 6 or 5 p.m.
There are a number of very interesting findings about dietary supplements. For instance, 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 testosterone
Within the following article, testosterone-replacement treatment refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that's manufactured 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.
Within four to six weeks, each one the guys had heightened levels of testosterone; none reported some side effects during the entire year they had been followed.
Because clomiphene citrate isn't 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's more capable of boosting testosterone than exogenous formulations. But unlike adrenal gland, clomiphene citrate preserves -- and potentially enriches -- sperm production. That makes medication such as clomiphene citrate one of only a few options for men with low testosterone that want to father children.
What kinds of testosterone-replacement treatment are available? *
The oldest form is the injection, which we use since it's inexpensive and because we faithfully become good testosterone levels in nearly everybody. The disadvantage is that a person should come in every few weeks to get 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 treatments help preserve a more uniform amount of blood testosterone. The first form of topical treatment has been a patch, but it has a quite 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 usage.
The most widely used testosterone preparation from the United States -- and also the one I start almost everyone off with -- is a topical gel. 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 tends to be absorbed to good levels in about 80% to 85 percent of guys, but leaves a significant number who do not consume sufficient for this to have a favorable impact. [For details on various formulations, see table below.]
Are there any drawbacks to using gels? How long does it take for them to work?
Men who begin using the implants need to return in to have their own testosterone levels measured again to be certain 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 fast, in just several doses. I normally measure it after 2 weeks, even although symptoms may not alter for a month or two.