A Harvard expert shares his Ideas on testosterone-replacement therapy
It might be stated that testosterone is the thing that makes men, guys. 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 at puberty, plays a role in sperm production, fuels libido, and leads to regular erections. It also fosters the creation of red blood cells, boosts mood, and aids cognition.
Over time, the testicular"machinery" which makes testosterone slowly becomes less effective, and testosterone levels start to drop, by about 1 percent per year, starting in the 40s. As guys get in their 50s, 60s, and beyond, they might begin to have signs and symptoms of low testosterone such as lower libido and sense of energy, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" significance low functioning and"gonadism" referring to the testicles). Researchers estimate that the condition 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 receiving treatment.
Much of the current debate focuses on the long-held belief that testosterone may stimulate prostate cancer.
He's developed particular 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 he thinks specialists should rethink the potential connection between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt that the average man to see a physician?
As a urologist, I have a tendency to see guys because they have sexual complaints. The main hallmark of reduced testosterone is low sexual libido or desire, but another can be erectile dysfunction, and some other man who complains of erectile dysfunction must get his testosterone level checked. Men can experience different symptoms, like more difficulty achieving an orgasm, less-intense orgasms, a much smaller amount of fluid out of 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 often discount these"soft symptoms" as a normal part of aging, but they're often treatable and reversible by decreasing testosterone levels.
Aren't those the same symptoms that guys have when they are treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are quite a few drugs that may lessen sex drive, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the quantity of the ejaculatory fluid, no wonder. However a reduction in orgasm intensity normally does not go together with treatment for BPH. Erectile dysfunction does not ordinarily go together with it either, though certainly if somebody has less sex drive or less attention, it is more of a struggle to have a fantastic erection.
How can you decide if or not a person is a candidate for testosterone-replacement therapy?
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 methods is far from ideal. Normally men with the lowest testosterone have the most symptoms and men with maximum testosterone have the least. But there are a number of guys who have reduced levels of testosterone in their blood and have no symptoms.
Looking at the biochemical numbers, The Endocrine Society* considers low testosterone for a entire testosterone level of less than 300 ng/dl, and I think that's a sensible guide. But no one quite agrees on a few. It's not like 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 publishes clinical practice guidelines with recommendations for who should and should not receive testosterone treatment. For a complete copy great site of the 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 another area of confusion and great debate, but I do not think that it's as confusing as it is apparently in 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 their testosterone that's circulating in the bloodstream is not readily available to cells. It's tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG. The biologically available portion of overall testosterone is called free testosterone, and it is readily available to the cells. Almost every lab has a blood test to measure free testosterone. Even though it's only a little fraction of this overall, the free testosterone level is a pretty good indicator of low testosterone. It's not ideal, but the correlation is greater compared to total testosterone.
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