A Harvard expert shares his Ideas on testosterone-replacement Treatment
An interview with Abraham Morgentaler, M.D.
It might be said that testosterone is the thing that makes men, guys. It gives them their characteristic deep voices, large muscles, and body and facial hair, differentiating them from women. It stimulates the development of the genitals at puberty, plays a role in sperm production, fuels libido, and leads to regular erections. It also boosts the production 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 fall, by approximately 1 percent per year, beginning in the 40s. As guys get in their 50s, 60s, and beyond, they may begin to have signs and symptoms of low testosterone such as reduced sex drive and sense of vitality, erectile dysfunction, diminished energy, reduced 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" speaking to the testicles). Yet it's an underdiagnosed issue, with only about 5% of these affected undergoing therapy.
Studies have shown that testosterone-replacement therapy can provide a wide range of benefits for men with hypogonadism, such as 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 may 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 expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he utilizes his patients, and why he believes experts should reconsider the possible connection between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt that the typical person to see a physician?
As a urologist, I have a tendency to see men because they have sexual complaints. The primary hallmark of low testosterone is low sexual desire or libido, but another can be erectile dysfunction, and any man who complains of erectile dysfunction should get his testosterone level checked. Men may experience other symptoms, such as more difficulty achieving an orgasm, less-intense orgasms, a smaller amount of fluid from ejaculation, and a feeling of numbness in the penis when they see or experience something that would normally be arousing.
The more of these symptoms there are, the more likely it is that a man has low testosterone. Many physicians tend to discount those"soft symptoms" as a normal part of aging, however, they are often treatable and reversible by normalizing testosterone levels.
Aren't those the same symptoms that men have when they're treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are quite a few medications which may reduce libido, such as the BPH drugs 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 along with treatment for BPH. Erectile dysfunction does not usually go together with it , though surely if a person has less sex drive or less interest, it is more of a struggle to have a good erection.
How do you decide if or not a man is a candidate for testosterone-replacement therapy?
There are just two ways 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 these two approaches is far from perfect. Generally guys with the lowest testosterone have the most symptoms and guys 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 signs.
Looking purely at the biochemical numbers, The Endocrine Society* believes low testosterone for a total testosterone level of less than 300 ng/dl, and I believe that is a reasonable guide. However, no one really agrees on a few. It's similar to diabetes, in which if your fasting glucose is over a certain level, they will say,"Okay, you've got it." With testosterone, that break point is not quite as apparent.
| *Notice: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and should not receive testosterone therapy. For a complete Visit This Link copy of these instructions, log on to www.endo-society.org. |
Is total testosterone the ideal thing to be measuring? Or if we are measuring something different?
Well, this is just another area of confusion and great discussion, but I do not think it's as confusing as it is apparently in the literature. When most physicians learned about testosterone in medical school, they learned about overall testosterone, or all of the testosterone in the body. However, about half of the testosterone that is circulating in the bloodstream is not available to cells. It is tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG.
The biologically available portion of total testosterone is known as free testosterone, and it's readily available to cells. Nearly every lab has a blood test to measure free testosterone. Though it's only a little fraction of this total, the free testosterone level is a fairly good indicator of low testosterone. It is not ideal, but the correlation is greater than with total testosterone.
This professional organization urges 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 Suggested for men who've
- Prostate or breast cancer
- a nodule on the prostate which can be felt during a DRE
- that 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 daily, diet, or other factors affect testosterone levels?
For many years, the recommendation has been to receive a testosterone value early in the morning because levels start to fall after 10 or 11 a.m.. However, the information 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 p.m. Between 6 and 2 p.m., it went down by 13 percent, a modest amount, and probably insufficient to influence diagnosis. Most guidelines nevertheless say it is important to do the test in the morning, however for men 40 and over, it probably doesn't matter much, provided that they obtain 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 those that have a diet low in protein have lower testosterone levels than men who consume more protein. But diet has not been researched thoroughly enough to make any recommendations that are clear.
Exogenous vs. endogenous testosteroneWithin the following article, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that is manufactured outside the body. Based upon the formula, treatment can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, reduced sperm count, increased red blood cell count, and additional side effects. In a recent prospective study, 36 hypogonadal men took a daily dose of clomiphene citrate for at least three months. Within four to six weeks, each one the men had heightened levels of testosteronenone reported any side effects during the year they were followed. Because clomiphene citrate isn't accepted by the FDA for use in males, little information exists regarding the long-term effects of carrying it (including the risk of developing prostate cancer) or whether it is more capable of boosting testosterone compared to exogenous formulas. But unlike adrenal gland, clomiphene citrate maintains -- and possibly enhances -- sperm production. That makes drugs like clomiphene citrate one of only a few choices for men with low testosterone who want to father children. |
What forms of testosterone-replacement therapy are available? *
The earliest form is an injection, which we use because it's inexpensive and because we reliably get fantastic testosterone levels in nearly everybody. The disadvantage is that a man needs to come in every few weeks to get a shot. A roller-coaster effect may also happen as blood testosterone levels peak and return to research.
Topical treatments help maintain a more uniform level of blood testosterone. The first kind of topical treatment has been a patch, but it has a very high rate of skin irritation. In one study, as many as 40 percent of people that used the patch developed a reddish area on their skin. That limits its usage.
The most widely used testosterone preparation from the United States -- and the one I start almost everyone off -- is a topical gel. According to my experience, it tends to be absorbed to good degrees in about 80% to 85 percent of men, but that leaves a significant number who do not consume sufficient for it to have a positive impact. [For details on various formulations, see table ]
Are there any drawbacks to using gels? How much time does it require them to work?
Men who start using the implants need to return in to have their testosterone levels measured again to be sure they're absorbing the proper amount. Our goal is that the mid to upper range of normal, which usually means approximately 500 to 600 ng/dl. The concentration of testosterone in the blood really goes up quite fast, within several doses. I usually measure it after 2 weeks, even though symptoms may not alter for a month or two.