A Harvard Specialist shares his Ideas on testosterone-replacement therapy
It might be stated that testosterone is the thing that makes men, men. It gives them their characteristic deep voices, large muscles, and facial and body hair, distinguishing them from women. It stimulates the growth of the genitals at puberty, plays a role in sperm production, fuels libido, and contributes to normal erections. Additionally, it boosts the creation of red blood cells, boosts mood, and assists cognition.
As time passes, the "machinery" which produces testosterone slowly becomes less powerful, and testosterone levels begin to drop, by approximately 1 percent 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 vitality, erectile dysfunction, decreased energy, reduced muscle mass and bone density, and anemia. Taken together, these signs and symptoms are often called 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.
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 ailments and male reproductive and sexual difficulties. He has developed specific experience in treating low testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment plans he utilizes his patients, and he believes specialists should rethink the possible link between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt the average person to see a doctor?
As a urologist, I have a tendency to observe men because they have sexual complaints. The main hallmark of low testosterone is low sexual desire or libido, but another may be erectile dysfunction, and any man who complains of erectile dysfunction must get his testosterone level checked. Men can experience different symptoms, such as more trouble achieving an orgasm, less-intense climaxes, a smaller amount of fluid out of ejaculation, and a feeling of numbness in the manhood when they see or experience something which would normally be arousing.
The more of the symptoms there are, the more likely it is that a man has low testosterone. Many physicians often dismiss those"soft symptoms" as a normal part of aging, but they're often treatable and reversible by decreasing testosterone levels.
Aren't those the very same symptoms that men have when they are treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are quite a few medications that 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 normally does not go together with treatment for BPH. Erectile dysfunction does not ordinarily go together with it either, though certainly if a person has less sex drive or less interest, it's more of a challenge to have a good erection.
How do you decide if a person is a candidate for testosterone-replacement therapy?
There are just two ways that we determine whether someone has low testosterone. One is a blood test and the other is by characteristic signs and symptoms, 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 have the least. But there are a number of men who have low levels of testosterone in their blood and have no signs.
Looking purely at the biochemical numbers, The Endocrine Society* believes low testosterone to be a total testosterone level of less than 300 ng/dl, and I believe that's a reasonable guide. However, no one quite agrees on a number. It is not like diabetes, where if your fasting sugar is over a certain level, they'll say,"Okay, you've got it." With testosterone, that break point isn't quite as apparent.
| *Note: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and should not click resources receive testosterone treatment. For a complete copy Source of these instructions, log hop over to these guys on to www.endo-society.org. |
Is total testosterone the right point to be measuring? Or if we are measuring something else?
Well, this is just another area of confusion and good debate, but I don't think that it's as confusing as it is apparently in the literature. When most doctors learned about testosterone in medical school, they learned about overall testosterone, or all of the testosterone in the body. But about half of the testosterone that's circulating in the blood isn't readily 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 overall testosterone is known as free testosterone, and it is readily available to cells. Nearly every laboratory has a blood test to measure free testosterone. Though it's just a small fraction of this overall, the free testosterone level is a fairly good indicator of reduced testosterone. It's not perfect, but the correlation is greater than with total testosterone.
This professional organization recommends testosterone therapy for men who have both
- 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 can be felt during a DRE
- a PSA greater than 3 ng/ml without additional analysis
- that 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 of day, diet, or other factors affect testosterone levels?
For years, the recommendation has been to get a testosterone value early in the morning because levels start to drop after 10 or 11 a.m.. But the data behind that recommendation were attracted to healthy young men. Two recent studies showed little change in blood glucose levels in men 40 and mature within the course of this day. One reported no change in typical testosterone till after 2 Between 6 and 2 p.m., it went down by 13%, a small amount, and probably insufficient to affect identification. Most guidelines nevertheless say it is important to perform the test in the morning, but for men 40 and over, it likely does not matter much, as long as they get their blood drawn before 5 or 6 p.m.
There are some very interesting findings about dietary supplements. By way of example, it appears that individuals who have a diet low in protein have lower testosterone levels than males who eat more protein. But diet hasn't been studied thoroughly enough to create any clear recommendations.
Exogenous vs. endogenous testosteroneWithin the following guide, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that's manufactured outside the body. Depending upon the formula, treatment can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, along with other side effects. Within four to six months, each one of the guys had increased levels of testosterone; none reported some side effects during the year they had been followed. Because clomiphene citrate is not accepted by the FDA for use in men, little information exists regarding the long-term ramifications of taking it (including the risk of developing prostate cancer) or if it is more capable of boosting testosterone compared to exogenous formulations. But unlike adrenal gland, clomiphene citrate maintains -- and potentially enhances -- sperm production. This makes drugs such as clomiphene citrate one of just a few choices for men with low testosterone that 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 almost everybody. The disadvantage is that a person needs to come in every couple of weeks to get a shot. A roller-coaster effect may also occur as blood testosterone levels peak and return to research.
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 high rate of skin irritation. In 1 study, as many as 40% of people that used the patch developed a red area in their skin. That limits its usage.
The most commonly used testosterone preparation from the United States -- and the one I begin almost everyone off with -- is a topical gel. There are just two brands: AndroGel and Testim. Based on my experience, it tends to be consumed to good degrees in about 80% to 85 percent of men, but leaves a significant number who do not absorb sufficient for it to have a favorable effect. [For details on several different formulations, see table below.]
Are there any downsides to using gels? How long does it require them to get the job done?
Men who start using the implants need to return in to have their testosterone levels measured again to be certain they're absorbing the right quantity. Our goal is the mid to upper assortment of normal, which generally means approximately 500 to 600 ng/dl. The concentration of testosterone in the blood really goes up quite fast, within a few doses. I normally measure it after 2 weeks, though symptoms may not alter for a month or two.