A Harvard expert shares his thoughts on testosterone-replacement therapy
It could be stated that testosterone is the thing that makes guys, guys. It gives them their characteristic deep voices, large muscles, and facial and body hair, distinguishing them from girls. It stimulates the development of the genitals , plays a role in sperm production, fuels libido, and contributes to normal erections. It also fosters the production of red blood cells, boosts mood, and aids cognition.
Over time, the testicular"machinery" that makes testosterone gradually 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 such as reduced libido and sense of energy, erectile dysfunction, diminished 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 only about 5% of these affected undergoing therapy.
But little consensus exists on 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 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 difficulties. He has developed particular expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he uses with his own patients, and he believes specialists should rethink the potential link between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt that the average man to find a physician?
As a urologist, I tend to see guys because they have sexual complaints. The primary hallmark of reduced testosterone is reduced sexual desire or libido, but another can be erectile dysfunction, and some other man who complains of erectile dysfunction should possess his testosterone level checked. Men may experience other symptoms, like more trouble achieving an orgasm, less-intense climaxes, a lesser quantity of fluid from ejaculation, and a sense of numbness in the manhood when they see or experience something that would usually be arousing.
The more of these symptoms there are, the more probable it is that a man has low testosterone. Many physicians tend to discount those"soft symptoms" as a normal part of aging, but they're often treatable and reversible by normalizing testosterone levels.
Are not those the very same symptoms that men have when they are treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are a number of medications that may reduce libido, including 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 doesn't go along with therapy for BPH. Erectile dysfunction does not usually go together with it either, though surely if somebody has less sex drive or less attention, it's more of a struggle to get a fantastic erection.
How do you decide whether or not a man is a candidate for testosterone-replacement treatment?
There are two ways we determine whether somebody has reduced testosterone. One is a blood test and the other is by characteristic signs and symptoms, and the correlation between those two approaches is far from perfect. Normally guys with the lowest testosterone have the most symptoms and men with maximum testosterone have the least. However, there are a number of men who have reduced 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 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 above a certain level, they will say,"Okay, you've got it." With testosterone, that break point isn't quite as clear.
| *Note: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and shouldn't receive testosterone therapy. See"Endocrine Society recommendations summarized." For try this site a complete copy read of these guidelines, log on to hop over to these guys www.endo-society.org. Is total testosterone the right point to be measuring? Or should we be measuring something different? Well, this is another area of confusion and good discussion, but I don't think it's as confusing as it appears to be from the literature. When most physicians learned about testosterone in medical school, they learned about total testosterone, or all of the testosterone in the human body. But about half of the testosterone that's circulating in the blood isn't available to the cells. The biologically available part of total testosterone is called free testosterone, and it is readily available to cells. Almost every lab has a blood test to measure free testosterone. Though it's just a little fraction of the total, the free testosterone level is a pretty good indicator of reduced testosterone. It is not ideal, but the correlation is greater than with total testosterone.
Do time of day, diet, or other factors affect testosterone levels? For many years, the recommendation has been to receive a testosterone value early in the morning since levels begin to fall after 10 or 11 a.m.. But the data behind that recommendation were drawn from healthy young men. Two recent studies showed little change in blood testosterone levels in men 40 and older over the course of this day. One reported no change in typical testosterone till after 2 Between 2 and 6 p.m., it went down by 13 percent, a small sum, and probably insufficient to affect identification. Most guidelines nevertheless say it's important to do the test in the morning, but for men 40 and above, it probably does not matter much, provided that they obtain their blood drawn before 6 or 5 p.m. There are a number of rather interesting findings about diet. For example, it appears that those that have a diet low in protein have lower testosterone levels than males who consume more protein. But diet hasn't been studied thoroughly enough to make any clear recommendations.
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