A Harvard expert shares his thoughts on testosterone-replacement therapy
It could 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 girls. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and leads to normal erections. Additionally, it boosts the production of red blood cells, boosts mood, and assists cognition.
Over time, the testicular"machinery" which makes testosterone slowly becomes less effective, and testosterone levels begin to fall, by about 1 percent per year, beginning in the 40s. As guys get in their 50s, 60s, and beyond, they may begin to have signs and symptoms of low testosterone such as reduced sex drive and sense of vitality, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often called hypogonadism ("hypo" significance low working and"gonadism" referring to the testicles). Yet it is an underdiagnosed problem, with just about 5% of those affected undergoing therapy.
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 reproductive and sexual difficulties. He has developed specific experience in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment strategies he uses with 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 that the typical person to find a physician?
As a urologist, I have a tendency to see men because they have sexual complaints. The main hallmark of reduced testosterone is reduced sexual libido or desire, but another may be erectile dysfunction, and some other guy who complains of erectile dysfunction should get his testosterone level checked. Men may experience other symptoms, such as more difficulty achieving an orgasm, less-intense orgasms, a smaller amount of fluid from ejaculation, and a sense of numbness in the penis when they see or experience something that would usually be arousing.
The more of the symptoms you will find, 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 same symptoms that men have when they're treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are a number of medications which may reduce libido, such as the BPH medication 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 , though certainly if somebody has less sex drive or less attention, it is more of a struggle to have a good erection.
How do you decide if or not a man 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 is by characteristic symptoms and signs, and the correlation between those two approaches is far from ideal. Normally men with the lowest testosterone have the most symptoms and men with highest testosterone have the least. However, there are a number of men who have low levels of testosterone in their blood and have no signs.
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 few. 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 clear.
| *Notice: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and should not receive Discover More Here testosterone therapy. For a complete copy of these instructions, log on to www.endo-society.org. Is complete testosterone the right thing to be measuring? Or if we are measuring something else? Well, 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 learned about total testosterone, or all of the testosterone in the body. However, about half of their testosterone that's circulating in the blood isn't available to cells. It's closely bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG. The available portion of total testosterone is called free testosterone, and it is readily available to the cells. Though it's just a small portion of the overall, the free testosterone level is a pretty good indicator of low testosterone. It is not perfect, but the significance is greater than with testosterone.
Do time daily, diet, or other factors affect testosterone levels? For many years, the recommendation has been to receive a testosterone value early in the morning because levels begin to drop after 10 or 11 a.m.. However, the data behind this recommendation were attracted to healthy young men. Two recent studies showed little change in blood testosterone levels in men 40 and mature over the course of the day. One reported no change in typical testosterone till after 2 p.m. Between 6 and 2 p.m., it went down by 13 percent, a small amount, and probably not enough to affect diagnosis. Most guidelines still say it is important to perform the test in the morning, but for men 40 and over, it likely does not matter much, as long as they get their blood drawn before 6 or 5 p.m. There are a number of rather interesting findings about diet. For instance, it seems that individuals who have a diet low in protein have lower testosterone levels than males who eat more protein. But diet has not been studied thoroughly enough to make any recommendations that are clear. In the following guide, testosterone-replacement treatment refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that is manufactured outside the body. Depending upon the formula, therapy can lead to skin irritation, breast enlargement and tenderness, sleep apnea, acne, reduced sperm count, increased red blood cell count, along with other side effects. Preliminary research has shown that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, may boost the creation of natural testosterone, also 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 isn't accepted by the FDA for use in males, little information exists regarding the long-term ramifications of carrying it (such as the probability of developing prostate cancer) or if it's more capable of boosting testosterone compared to exogenous formulas. But unlike adrenal gland, clomiphene citrate maintains -- and potentially enhances -- sperm production. That makes medication such as clomiphene citrate one of just a few options for men with low testosterone who want to father children. What kinds of testosterone-replacement therapy are available? * The oldest form is an injection, which we use because it's inexpensive and because we reliably become fantastic testosterone levels in almost everybody. The drawback is that a person needs to come in every few weeks to find a shot. A roller-coaster effect may also happen as blood testosterone levels peak and then return to research. Topical treatments help maintain a more uniform level of blood testosterone. The first kind of topical treatment was a patch, but it has a very large rate of skin irritation. In 1 study, as many as 40% of men who used the patch developed a reddish area in their skin. That limits its use. The most widely used testosterone preparation in the United States -- and the one I begin almost everyone off -- is a topical gel. There are two brands: AndroGel and Testim. 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 impact. [For specifics on various formulations, see table ] 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 the blood actually goes up quite fast, within several doses. I usually measure it after 2 weeks, although symptoms may not change for a month or two. |