A Harvard expert shares his Ideas on testosterone-replacement therapy
It could be stated that testosterone is the thing that makes guys, guys. It gives them their characteristic deep voices, big muscles, and body and facial hair, distinguishing them from girls. It stimulates the development of the genitals at puberty, plays a role in sperm production, fuels libido, and leads to normal erections. It also boosts the production of red blood cells, boosts mood, and aids cognition.
Over time, the testicular"machinery" that produces testosterone gradually becomes less powerful, and testosterone levels start to drop, by about 1 percent a year, starting in the 40s. As men get in their 50s, 60s, and beyond, they might start to have symptoms and signs of low testosterone such as reduced sex drive and sense of vitality, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and nausea. Taken together, these signs and symptoms are often referred to as hypogonadism ("hypo" significance low functioning and"gonadism" speaking to the testicles). Researchers estimate that the condition affects anywhere from two to six million men in the USA. Yet it's an underdiagnosed problem, with just about 5 percent of these affected receiving treatment.
Various studies have shown that testosterone-replacement therapy may offer a wide range of benefits for men with hypogonadism, such as enhanced libido, mood, cognition, muscle mass, bone density, and red blood cell production. But little consensus exists on what constitutes low testosterone, when testosterone supplementation makes sense, or what risks patients face.
He has developed particular experience in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he utilizes his patients, and he believes specialists should rethink the possible link between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt the average person to find a doctor?
As a urologist, I tend to see guys since they have sexual complaints. The primary hallmark of low testosterone is low sexual libido or desire, but another may be erectile dysfunction, and some other man who complains of erectile dysfunction should possess his testosterone level checked. Men can experience different symptoms, such as more difficulty achieving an orgasm, less-intense climaxes, a much smaller amount 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 you will find, the more probable it is that a man has low testosterone. Many physicians often discount these"soft symptoms" as a normal part of aging, however, they are often treatable and reversible by normalizing testosterone levels.
Are not those the same symptoms that guys have when they're treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are quite a few medications that may lessen sex drive, including 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 therapy for BPH. Erectile dysfunction does not usually go along with it , though surely if somebody has less sex drive or less attention, it's more of a challenge to have a good erection.
How can you determine whether or not a man is a candidate for testosterone-replacement treatment?
There are just two ways that we determine whether someone has reduced testosterone. One is a blood test and the other is by characteristic symptoms and signs, and the correlation between those two approaches is far from ideal. Normally men with the lowest testosterone have the most symptoms and men with highest testosterone possess the least. But there are some men who have reduced levels of testosterone in their blood and have no signs.
Looking purely 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 sensible guide. But no one quite 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.
| *Note: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and should try this site not receive testosterone treatment. See"Endocrine Society recommendations summarized." click for info For a complete copy of these instructions, log on try this out to www.endo-society.org. |
Is complete testosterone the ideal point to be measuring? Or if we are measuring something different?
This is another area of confusion and great debate, but I don't think it's as confusing as it is apparently from the literature. When most doctors learned about testosterone in medical school, they learned about total testosterone, or all the testosterone in the body. But about half of the testosterone that is circulating in the blood isn't readily available to cells.
The biologically available portion of overall testosterone is known as free testosterone, and it is readily available to the cells. Though it's only a small portion of this total, the free testosterone level is a pretty good indicator of reduced testosterone. It is not perfect, but the correlation is greater compared to testosterone.
This professional organization recommends testosterone therapy for men who have
- Reduced levels of testosterone in the blood (less than 300 ng/dl)
- symptoms of low testosterone.
Therapy is not recommended for men who have
- Prostate or breast cancer
- a nodule on the prostate which may be felt during a DRE
- a PSA higher than 3 ng/ml without further analysis
- a hematocrit greater than 50% or thick, viscous blood
- untreated obstructive sleep apnea
- severe lower urinary tract infections
- class III or IV heart failure.
Do time of day, diet, or other elements affect testosterone levels?
For many years, the recommendation has been to receive a testosterone value early in the morning because levels begin to drop after 10 or even 11 a.m.. But the information behind this 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 until after 2 p.m. Between 2 and 6 p.m., it went down by 13%, a small amount, and probably insufficient to affect identification. Most guidelines still say it is important to perform the evaluation in the morning, but for men 40 and above, it likely doesn't matter much, as long as they obtain their blood drawn before 6 or 5 p.m.
There are a number of rather interesting findings about dietary supplements. For instance, it appears that individuals that 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 recommendations that are clear.
In the following article, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that's produced outside the body. Depending upon the formula, therapy can cause skin irritation, breast tenderness and enlargement, sleep apnea, acne, reduced sperm count, increased red blood cell count, along with other side effects.
Preliminary studies have proven that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, can boost the production of natural testosterone, known as endogenous testosterone, in men. Within four to six weeks, all of the guys had heightened levels of testosteronenone reported any side effects during the year they were followed.
Since 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's more effective at boosting testosterone compared to exogenous formulations. But unlike adrenal gland, clomiphene citrate preserves -- and possibly enriches -- sperm production. This makes drugs such as clomiphene citrate one of only a few choices for men with low testosterone that want to father children.
What forms of testosterone-replacement therapy can be found? *
The oldest form is the injection, which we still use since it's inexpensive and since we reliably get fantastic testosterone levels in nearly everybody. The drawback is that a person should come in every few weeks to find a shot. A roller-coaster effect may also occur as blood testosterone levels peak and return to baseline. [See"Exogenous vs. endogenous testosterone," above.]
Topical therapies help preserve a more uniform level of blood testosterone. The first form of topical treatment was a patch, but it has a very high rate of skin irritation. In 1 study, as many as 40% of men who used the patch developed a reddish area in their skin. That limits its use.
The most commonly used testosterone preparation in the United States -- and the one I begin almost everyone off -- is a topical gel. According to my experience, it has a tendency to be consumed to great degrees in about 80% to 85 percent of guys, but leaves a substantial number who do not consume sufficient for this to have a positive effect. [For specifics on various formulations, see table below.]
Are there any drawbacks to using gels? 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 certain they are absorbing the right amount. Our goal is that the mid to upper assortment of normal, which generally means approximately 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, although symptoms may not change for a month or two.