A Harvard Specialist shares his thoughts on testosterone-replacement therapy
It might be stated that testosterone is the thing that makes guys, men. It gives them their characteristic deep voices, big muscles, and facial and body hair, distinguishing them from women. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and contributes to normal erections. Additionally, it fosters the creation of red blood cells, boosts mood, and aids cognition.
Over time, the "machinery" that makes testosterone slowly becomes less powerful, and testosterone levels begin to fall, by approximately 1% a year, starting in the 40s. As men get into their 50s, 60s, and beyond, they might start to have symptoms and signs of low testosterone like lower sex drive and sense of energy, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and anemia. Taken together, these symptoms and signs are often called hypogonadism ("hypo" meaning low working and"gonadism" speaking to the testicles). Yet it is an underdiagnosed issue, with just about 5% of those affected undergoing therapy.
Studies have shown that testosterone-replacement therapy may provide a vast selection of advantages for men with hypogonadism, including 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 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 ailments and male sexual and reproductive difficulties. He has developed particular experience in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment strategies he uses with his own patients, and why he thinks specialists should rethink the potential link between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt the average person to find a doctor?
As a urologist, I tend 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 some other guy who complains of erectile dysfunction must possess his testosterone level checked. Men may experience other symptoms, such as 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 usually be arousing.
The more of the symptoms you will find, the more probable 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 normalizing testosterone levels.
Aren't those the same symptoms that guys have when they are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are quite a few medications that may lessen sex drive, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the amount of the ejaculatory fluid, no question. But a decrease in orgasm intensity normally doesn't go together with treatment for BPH. Erectile dysfunction does not usually go along with it either, though certainly if somebody has less sex drive or less interest, it's more of a struggle to have a good erection.
How do you determine whether or not a man is a candidate for testosterone-replacement therapy?
There are just two ways that we determine whether somebody has reduced 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 guys with the lowest testosterone have the most symptoms and guys with highest testosterone have the least. But there are some 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 think that's a sensible guide. However, no one quite agrees on a few. It's similar to diabetes, in which if your fasting glucose is above a certain level, they'll 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 should not like this receive testosterone therapy. Watch"Endocrine Society recommendations summarized." Is complete testosterone the ideal thing to be measuring? Or if we are measuring something else? Well, this is just another area of confusion and good discussion, 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 of the testosterone in the human body. However, about half of their testosterone that's circulating in the bloodstream is not readily available to the cells. It's tightly bound to a carrier molecule called 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. Though it's only a little portion 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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