A Harvard expert shares his Ideas on testosterone-replacement therapy
It might be stated that testosterone is what makes guys, men. It gives them their characteristic deep voices, big muscles, and facial and body 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 normal erections. Additionally, it fosters the production of red blood cells, boosts mood, and assists cognition.
Over time, the "machinery" which produces testosterone gradually becomes less powerful, and testosterone levels begin to fall, by approximately 1 percent a year, starting in the 40s. As guys get in their 50s, 60s, and beyond, they may start to have symptoms and signs of low testosterone such as reduced libido and sense of vitality, erectile dysfunction, diminished 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" speaking to the testicles). Yet it's an underdiagnosed problem, with only about 5 percent of those affected receiving treatment.
Various studies have shown that testosterone-replacement therapy can provide a wide range of advantages for men with hypogonadism, such as improved libido, mood, cognition, muscle mass, bone density, and red blood cell production. But little consensus exists about what constitutes low testosterone, when testosterone supplementation makes sense, or what dangers patients face. Much of the current debate focuses on the long-held belief that testosterone can stimulate prostate cancer.
He's developed particular expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he utilizes his patients, and he thinks experts should reconsider the potential connection between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt the average man to find a physician?
As a urologist, I have a tendency to observe guys since 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 can experience different symptoms, like more difficulty achieving an orgasm, less-intense climaxes, a much lesser quantity of fluid out of ejaculation, and a sense of numbness in the manhood when they see or experience something which would usually 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 those"soft symptoms" as a normal part of aging, however, they're often treatable and reversible by decreasing testosterone levels.
Are not those the very same symptoms that guys have when they are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are quite a few drugs which may reduce libido, such as the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the amount of the ejaculatory fluid, no question. However a decrease in orgasm intensity normally doesn't go together with therapy for BPH. Erectile dysfunction does not usually go along with it either, though certainly if a person has less sex drive or less attention, it is more of a struggle to get a good erection.
How do you determine whether or not 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 one is by characteristic signs and symptoms, and the correlation between those two methods 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 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* considers low testosterone to be a entire testosterone level of less than 300 ng/dl, and I believe that is a reasonable guide. However, no one really agrees on a number. It is similar to diabetes, in which if your fasting sugar is over a certain level, they will say,"Okay, you've got it." With testosterone, that break point is not quite as apparent.
| *Note: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and shouldn't receive testosterone treatment. For a complete copy of these guidelines, log on to www.endo-society.org. Is total testosterone the right point to be measuring? Or if we are measuring something different? This is just another area of confusion and great discussion, but I do not think it's as confusing as it is apparently from the literature. When most physicians learned about testosterone in medical school, they heard about overall testosterone, or all of the testosterone in the body. However, about half of the testosterone that's circulating in the bloodstream isn't readily available to the cells. It is tightly bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG. The biologically available portion of overall testosterone is known as free testosterone, and it's readily available to cells. Even though it's just a little fraction of the total, the free testosterone level is a fairly good indicator of low testosterone. It is not perfect, but the significance is greater compared to total testosterone.
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