A Harvard expert 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 body and facial hair, distinguishing them from women. It stimulates the development of the genitals , plays a role in sperm production, fuels libido, and leads to normal erections. It also boosts the creation of red blood cells, boosts mood, and aids cognition.
Over time, the "machinery" which makes testosterone gradually becomes less powerful, and testosterone levels start to drop, by approximately 1% per 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 like lower libido and sense of vitality, erectile dysfunction, decreased energy, decreased muscle mass and bone density, and anemia. Taken together, these symptoms and signs are often referred to as 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 issue, with only about 5 percent of those affected undergoing therapy.
Studies have revealed that testosterone-replacement therapy can offer a vast range of advantages for men with hypogonadism, including enhanced libido, mood, cognition, muscle mass, bone density, and red blood cell production. 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 diseases and male sexual and reproductive problems. 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 visit the websitetry this site and diagnosisWhat symptoms and signs of low testosterone prompt the average person to see a physician?
As a urologist, I tend to see men since they have sexual complaints. The primary hallmark of reduced testosterone is reduced sexual desire or libido, but another may be erectile dysfunction, and any man who complains of erectile dysfunction must possess his testosterone level checked. Men may experience different symptoms, like more difficulty achieving an orgasm, less-intense climaxes, a much smaller quantity of fluid out of ejaculation, and a feeling of numbness in the penis when they see or experience something which would usually be arousing.
The more of these symptoms you will find, the more probable it is that a man has low testosterone. Many physicians tend to dismiss those"soft symptoms" as a normal part of aging, however, they are 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 medications that may lessen sex drive, such as the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the quantity of the ejaculatory fluid, no wonder. But a reduction in orgasm intensity usually doesn't go together with therapy for BPH. Erectile dysfunction does not usually go along with it either, though surely if a person has less sex drive or less attention, it's more of a challenge to get a fantastic 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 symptoms and signs, and the correlation between these two approaches is far from ideal. Normally men with the lowest testosterone have the most symptoms and men with maximum testosterone possess the least. But there are some men who have low levels of testosterone in their blood and have no symptoms.
Looking purely 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 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. |
Is total testosterone the right thing to be measuring? Or should we be measuring something else?
This is just another area of confusion and good discussion, but I do not think that it's as confusing as it appears to be in the literature. When most doctors learned about testosterone in medical school, they heard about overall testosterone, or all of the testosterone in the human body. But about half of the testosterone that's circulating in the bloodstream isn't readily available to cells. It is closely bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG.
The available portion of overall testosterone is called free testosterone, and it's readily available to the cells. Though it's just a small fraction of the overall, the free testosterone level is a fairly good indicator of reduced testosterone. It's not perfect, but the correlation is greater compared to 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've
- 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 percent 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 many years, the recommendation was to get a testosterone value early in the morning since levels begin to drop after 10 or even 11 a.m.. But the data behind this recommendation were drawn from healthy young men. Two recent studies showed little change in blood glucose levels in men 40 and older over the course of this day. One reported no change in typical testosterone until after 2 Between 6 and 2 p.m., it went down by 13 percent, a modest amount, and probably not enough to affect diagnosis. Most guidelines still say it is important to do the evaluation in the morning, but for men 40 and above, it likely does not 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 appears that those who have a diet low in protein have lower testosterone levels than males who consume more protein. But diet has not been researched thoroughly enough to make any recommendations that are clear.
Within this guide, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that is produced outside the body. Depending on the formula, treatment can lead to skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, and additional side effects.
Within four to six weeks, each one of the men had increased levels of testosterone; none reported any side effects throughout the year they were followed.
Since clomiphene citrate isn't approved by the FDA for use in males, little information exists regarding the long-term effects of carrying it (such as the risk of developing prostate cancer) or whether it's more capable of boosting testosterone than exogenous formulas. But unlike adrenal gland, clomiphene citrate preserves -- and possibly enriches -- sperm production. This 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 treatment can be found? *
The earliest form is an injection, which we still use because it is cheap and since we reliably get fantastic testosterone levels in nearly everybody. The disadvantage is that a person should come in every couple of weeks to find a shot. A roller-coaster effect can also occur as blood testosterone levels peak and then return to research. [Watch"Exogenous vs. endogenous testosterone," above.]
Topical treatments help preserve a more uniform level of blood testosterone. The first form of topical therapy has been a patch, but it has a quite large rate of skin irritation. In 1 study, as many as 40 percent of men who used the patch developed a red area on their skin. That limits its use.
The most commonly used testosterone preparation in the United States -- and also the one I begin almost everyone off -- is a topical gel. The gel comes from tiny tubes or within a unique dispenser, and you rub it on your shoulders or upper arms once a day. According to my experience, it has a tendency to be consumed to great levels in about 80% to 85% of men, but that 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 drawbacks to using dyes? How much time does it require them to get the job done?
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 proper quantity. Our goal is that the mid to upper assortment of normal, which generally 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.