A Harvard Specialist shares his thoughts on testosterone-replacement therapy
A meeting with Abraham Morgentaler, M.D.
It might be said that testosterone is what makes men, guys. It gives them their characteristic deep voices, big muscles, and body and facial hair, distinguishing them from girls. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and contributes to regular erections. Additionally, it boosts the creation of red blood cells, boosts mood, and aids cognition.
Over time, the "machinery" which produces testosterone gradually becomes less powerful, and testosterone levels begin to fall, by approximately 1% a year, starting in the 40s. As guys get in their 50s, 60s, and beyond, they may start to have signs and symptoms of low testosterone like lower sex drive and sense of vitality, erectile dysfunction, decreased energy, decreased muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" significance low working and"gonadism" referring to the testicles). Yet it's an underdiagnosed issue, with only about 5 percent of those affected undergoing therapy.
Various studies have revealed that testosterone-replacement therapy may provide a wide selection of advantages for men with hypogonadism, including improved libido, mood, cognition, muscle mass, bone density, and red blood cell production.
He's developed particular expertise 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 thinks specialists should rethink the potential connection between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt that the typical person to find a physician?
As a urologist, I have a tendency to observe guys because 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 guy who complains of erectile dysfunction must get his testosterone level checked. Men can experience different symptoms, like more difficulty achieving an orgasm, less-intense climaxes, a much smaller quantity of fluid from ejaculation, and a feeling of numbness in the penis when they see or experience something that would usually be arousing.
The more of these symptoms there are, the more likely it is that a man has low testosterone. Many physicians often discount those"soft symptoms" as a normal part of aging, but they are often treatable and reversible by decreasing testosterone levels.
Are not those the same symptoms that guys have when they are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are a number of medications which may lessen sex drive, such as the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs may also decrease the quantity of the ejaculatory fluid, no question. However a reduction in orgasm intensity usually doesn't go along with treatment for BPH. Erectile dysfunction does not usually go along with it , though surely if a person has less sex drive or less attention, it is more of a challenge to have a good erection.
How do you determine whether a person is a candidate for testosterone-replacement therapy?
There are two ways that we determine whether somebody has low testosterone. One is a blood test and the other one is by characteristic signs and symptoms, and the correlation between those two approaches is far from perfect. Normally guys with the lowest testosterone have the most symptoms and men with maximum testosterone possess the least. But there are a number of guys who have low levels of testosterone in their blood and have no signs.
Looking at the biochemical numbers, The Endocrine Society* believes low testosterone for a total testosterone level of less than 300 ng/dl, and I think that is a reasonable guide. But no one really agrees on a number. It's not like diabetes, where if your fasting sugar is above a certain level, they will say,"Okay, you've got it." With testosterone, that break point is not quite as clear.
| *Notice: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and shouldn't have a peek at this site receive testosterone therapy. See"Endocrine Society recommendations summarized." you can look here For a complete copy of these instructions, log on to www.endo-society.org. |
Is total testosterone the ideal point to be measuring? Or should we be measuring something different?
Well, this is another area of confusion and good debate, but I don't think it's as confusing as it appears to be in the literature. When most physicians learned about testosterone in medical school, they heard about overall testosterone, or all the testosterone in the human body. However, about half of their testosterone that's circulating in the blood is not available to cells.
The available part of overall testosterone is known as free testosterone, and it is readily available to cells. Though it's just a little fraction of the 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 urges testosterone treatment for men who have both
Therapy is not Suggested for men who've
- Breast or prostate cancer
- a nodule on the prostate which may be felt during a DRE
- that a PSA greater than 3 ng/ml without additional analysis
- a hematocrit greater than 50 percent or thick, viscous blood
- untreated obstructive sleep apnea
- severe lower urinary tract infections
- class III or IV heart failure.
Do time daily, diet, or other elements influence testosterone levels?
For many years, the recommendation was to receive a testosterone value early in the morning since levels begin to fall after 10 or 11 a.m.. But the data behind that recommendation were drawn from healthy young men. Two recent studies demonstrated 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 influence diagnosis. Most guidelines nevertheless say it's important to do 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 5 or 6 p.m.
There are some rather interesting findings about dietary supplements. For example, it appears that individuals who 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.
FormulationsExogenous vs. endogenous testosterone
Within the following guide, testosterone-replacement treatment refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that is 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, and additional side effects.
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, all of the guys had heightened levels of testosterone; none reported any side effects during the entire year they had been followed.
Because clomiphene citrate is not approved by the FDA for use in males, little information exists about the long-term effects of carrying it (such as the probability of developing prostate cancer) or if it's more capable of boosting testosterone than exogenous formulas. But unlike adrenal gland, clomiphene citrate maintains -- and possibly enriches -- sperm production. That makes drugs like clomiphene citrate one of just a few options for men with low testosterone who want to father children.
What forms of testosterone-replacement therapy are available? *
The earliest form is the injection, which we still use since it's inexpensive and because we faithfully become fantastic testosterone levels in nearly everybody. The drawback is that a person needs to come in every few weeks to find a shot. A roller-coaster effect can also happen as blood glucose levels peak and then return to research. [Watch"Exogenous vs. endogenous testosterone," above.]
Topical treatments help preserve a more uniform amount of blood testosterone. The first form of topical treatment was a patch, but it has a very large rate of skin irritation. In 1 study, as many as 40% of people that used the patch developed a red area on their skin. That restricts its use.
The most widely used testosterone preparation in the United States -- and also the one I start almost everyone off with -- is a topical gel. There are two brands: AndroGel and Testim. According to my experience, it tends to be consumed to good levels in about 80% to 85% of men, but that leaves a significant number who don't consume enough for this to have a positive effect. [For details on various formulations, see table ]
Are there any drawbacks 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 own testosterone levels measured again to be sure they are absorbing the proper amount. Our target is that the mid to upper range of normal, which usually means around 500 to 600 ng/dl. The concentration of testosterone in blood actually goes up quite quickly, in just a few doses. I usually measure it after 2 weeks, although symptoms may not alter for a month or two.