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 , 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" that produces testosterone gradually becomes less effective, 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 start to have symptoms and signs of low testosterone such as lower libido and sense of vitality, erectile dysfunction, decreased energy, decreased muscle mass and bone density, and anemia. Taken together, these signs and symptoms 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.
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 ailments and male sexual and reproductive difficulties. He's developed specific experience 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 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 typical person to see a doctor?
As a urologist, I tend to see men since they have sexual complaints. The main hallmark of reduced 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 can experience different symptoms, like more trouble achieving an orgasm, less-intense orgasms, a smaller amount of fluid from ejaculation, and a feeling of numbness in the penis when they see or experience something that would normally 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're treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are a number of 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 question. But a decrease in orgasm intensity normally does not go along with treatment for BPH. Erectile dysfunction does not usually go along with it either, though certainly if somebody has less sex drive or less attention, it's more of a struggle to have a fantastic erection.
How can you determine whether a man is a candidate for testosterone-replacement treatment?
There are just two ways we determine whether someone has reduced testosterone. One is a blood test and the other one is by characteristic signs and symptoms, and the correlation between these two methods is far from perfect. Normally guys with the lowest testosterone have the most symptoms and guys with highest 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 purely at the biochemical numbers, The Endocrine Society* believes low testosterone to be a total testosterone level of less than 300 ng/dl, and I believe 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 above a certain level, they'll say,"Okay, you've got it." With testosterone, that break point isn't quite as apparent.
| *Note: The Endocrine Society publishes clinical practice guidelines my response with recommendations for who should and should not receive testosterone treatment. Is complete testosterone the ideal thing to be measuring? Or if we are measuring something else? This is just another area of confusion and great debate, but I do not think it's as confusing as it is apparently from the literature. When most doctors learned about testosterone in medical school, they heard about overall testosterone, or all the testosterone in the human body. But about half of their testosterone that is circulating in the bloodstream isn't available to cells. It is closely bound to a carrier molecule called 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. Nearly every lab has a blood test to measure free testosterone. Even though it's just a small 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 total testosterone. This professional organization urges testosterone treatment for men who have both
Therapy is not Suggested for men who have
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Do time of day, diet, or other elements affect testosterone levels?
For years, the recommendation was to get a testosterone value early in the morning since levels begin to drop after 10 or even 11 a.m.. But the data behind this recommendation were drawn from healthy young men. Two recent studies showed little change in blood glucose levels in men 40 and older over the course of this day. One reported no change in average testosterone until after 2 Between 6 and 2 p.m., it went down by 13 percent, a modest amount, and probably insufficient to influence diagnosis. Most guidelines nevertheless say it is important to do the test in the morning, however for men 40 and above, it likely does not matter much, as long as they obtain their blood drawn before 6 or 5 p.m.
There are some rather interesting findings about dietary supplements. For instance, it seems that individuals that have a diet low in protein have lower testosterone levels than males who eat more protein. But diet hasn't been studied thoroughly enough to create any clear recommendations.
Within the following article, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that is manufactured outside the body. Depending upon the formula, treatment can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, along with additional side effects.
Preliminary studies have shown that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, may boost the creation of natural testosterone, termed endogenous testosterone, in men. Within four to six weeks, all of the men had heightened levels of testosterone; none reported any side effects during the year they were followed.
Because clomiphene citrate is not approved by the FDA for use in men, little information exists about the long-term effects of taking it (including the risk of developing prostate cancer) or whether it is more effective at boosting testosterone than exogenous formulations. But unlike exogenous testosterone, clomiphene citrate preserves -- and possibly enhances -- sperm production. This makes medication such as clomiphene citrate one of just a few options for men with low testosterone that want to father children.
FormulationsWhat forms of testosterone-replacement therapy are available? *
The oldest form is the injection, which we use because it's inexpensive and since we faithfully become fantastic testosterone levels in nearly everybody. The disadvantage is that a man should come in every couple of weeks to find a shot. A roller-coaster effect can also occur as blood testosterone levels peak and return to baseline. [See"Exogenous vs. endogenous testosterone," above.]
Topical therapies help preserve a more uniform amount of blood testosterone. The first form of topical therapy has been a patch, but it has a quite high rate of skin irritation. In one study, as many as 40 percent of people that used the patch developed a red area on their skin. That restricts its usage.
The most commonly used testosterone preparation in the United States -- and also the one I begin almost everyone off with -- is a topical gel. According to my experience, it has a tendency to be absorbed to good degrees in about 80% to 85 percent of men, but leaves a substantial number who don't consume enough for it to have a favorable effect. [For specifics on several different formulations, see table below.]
Are there any drawbacks to using dyes? How long does it take for them to get the job done?
Men who begin using the gels have to return in to have their own testosterone levels measured again to make certain they are absorbing the right quantity. Our target is the mid to upper assortment of normal, which usually means approximately 500 to 600 ng/dl. The concentration of testosterone in blood actually goes up quite quickly, in just a few doses. I normally measure it after two weeks, although symptoms may not alter for a month or two.