A Harvard expert shares his Ideas on testosterone-replacement therapy
An interview with Abraham Morgentaler, M.D.
It might be said that testosterone is what makes guys, guys. 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 contributes to regular erections. It also boosts the production of red blood cells, boosts mood, and aids cognition.
As time passes, the testicular"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 into their 50s, 60s, and beyond, they might begin to have signs and symptoms of low testosterone like lower sex drive and sense of energy, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often called hypogonadism ("hypo" meaning low working and"gonadism" referring to the testicles). Researchers estimate that the illness affects anywhere from two to six million men in the USA. Yet it is an underdiagnosed problem, with just about 5 percent of these affected undergoing therapy.
But little consensus exists on what constitutes low testosterone, when testosterone supplementation makes sense, or what risks patients face. Much of the current debate focuses on the long-held belief that testosterone may stimulate prostate cancer.
He's developed specific expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment strategies he utilizes his patients, and why he believes 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 see a doctor?
As a urologist, I tend to observe 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 can experience different symptoms, like more trouble 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 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 dismiss these"soft symptoms" as a normal part of aging, but they are often treatable and reversible by decreasing testosterone levels.
Are not those the very same symptoms that men have when they're treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are a number of drugs that may reduce libido, such as the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the amount of the ejaculatory fluid, no question. But a reduction in orgasm intensity normally doesn't go together with treatment for BPH. Erectile dysfunction does not usually go along with it , though certainly if somebody has less sex drive or less interest, it is more of a struggle to have a good erection.
How do you determine whether or not a person is a candidate for testosterone-replacement treatment?
There are two ways that we determine whether someone has reduced testosterone. One is a blood test and the other one is by characteristic symptoms and signs, and the correlation between those two approaches is far from ideal. Generally men with the lowest testosterone have the most symptoms and guys with maximum testosterone have the least. But there are a number of guys who have low levels of testosterone in their blood and have no symptoms.
Looking at the biochemical numbers, The Endocrine Society* believes low testosterone for a total testosterone level of less than 300 ng/dl, and I think that is a reasonable guide. But no one really agrees on a number. 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 publishes clinical practice guidelines with recommendations for who should and should not receive testosterone treatment. For a complete copy of the instructions, explanation log on to www.endo-society.org. Is total testosterone the right point to be measuring? Or should we be measuring something else? This is another area of confusion and good debate, but I don't think that it's as confusing as it appears to be from the literature. When most doctors learned about testosterone in medical school, they heard about total testosterone, or all the testosterone in the human body. But about half of their testosterone that's circulating in the blood is not readily available to the cells. It is tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG. The available portion of total testosterone is known as free testosterone, and it's readily available to cells. Though it's only a little fraction of the overall, the free testosterone level is a pretty good indicator of reduced testosterone. It's not ideal, but the correlation is greater compared to testosterone.
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