A Harvard Specialist 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, big muscles, and facial and body hair, differentiating them from girls. 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 assists cognition.
As time passes, the testicular"machinery" that produces testosterone gradually becomes less effective, and testosterone levels begin to drop, by about 1 percent per year, beginning in the 40s. As guys get in their 50s, 60s, and beyond, they may begin to have symptoms and signs of low testosterone such as lower libido and sense of energy, erectile dysfunction, decreased energy, reduced muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" meaning low functioning and"gonadism" referring to the testicles). Yet it is an underdiagnosed issue, with only about 5 percent of those affected receiving treatment.
Much of the current debate focuses on the long-held belief that testosterone may stimulate prostate cancer.
He has developed specific expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment strategies he utilizes his own patients, and he believes experts should reconsider the potential connection between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt the typical man to see a physician?
As a urologist, I tend to observe men since they have sexual complaints. The main hallmark of low 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 difficulty achieving an orgasm, less-intense orgasms, a much smaller amount of fluid out of ejaculation, and a feeling of numbness in the penis when they see or experience something which would usually be arousing.
The more of these symptoms you will find, the more likely it is that a man has low testosterone. Many physicians tend to dismiss those"soft symptoms" as a normal part of aging, however, they are 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 which may lessen sex drive, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs may also decrease the amount of the ejaculatory fluid, no question. However a decrease in orgasm intensity usually does not go along with therapy for BPH. Erectile dysfunction does not ordinarily go along with it either, though certainly if somebody has less sex drive or less attention, it is more of a struggle to get a good erection.
How do you decide if a person is a candidate for testosterone-replacement treatment?
There are two ways that we determine whether somebody has low 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 perfect. Normally guys with the lowest testosterone have the most symptoms and guys with highest testosterone have the least. But there are some men who have low levels of testosterone in their blood and have no symptoms.
Looking purely at the biochemical amounts, The Endocrine Society* believes low testosterone for a total testosterone level of less than 300 ng/dl, and I think that's a reasonable guide. But no one really agrees on a few. It is similar to diabetes, in which if your fasting sugar is over a certain level, they will say,"Okay, you've got it." With testosterone, that break point isn't quite as apparent.
| *Notice: The Endocrine Society recommends clinical practice guidelines with recommendations for who This Site should and should not Extra resources receive testosterone treatment. Is complete testosterone the ideal point to be measuring? Or if we are measuring something different? This is just another area of confusion and good discussion, but I do not think that it's as confusing as it is apparently in the literature. When most doctors 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 bloodstream is not readily available to cells. It's closely bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG. The biologically available portion of overall testosterone is known as free testosterone, and it's readily available to the cells. Even though it's only a little fraction of this overall, the free testosterone level is a fairly good indicator of low testosterone. It's not perfect, but the significance is greater compared to total testosterone.
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 because levels begin to drop after 10 or 11 a.m.. However, the information behind that recommendation were attracted to healthy young men. Two recent studies showed little change in blood glucose levels in men 40 and mature within 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 modest sum, and probably not enough to affect identification. Most guidelines still say it is important to do the test in the morning, however for men 40 and above, it likely doesn't matter much, provided that they get their blood drawn before 6 or 5 p.m. There are a number of very interesting findings about dietary supplements. For instance, it appears that those who have a diet low in protein have lower testosterone levels than males who consume more protein. But diet has not been studied thoroughly enough to create any recommendations that are clear. In the following article, testosterone-replacement treatment refers to the treatment of hypogonadism with adrenal gland -- testosterone that is manufactured outside the body. Based on the formula, treatment can lead to skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, and additional side effects. Within four to six weeks, each one of the men had increased levels of testosterone; none reported some side effects during the entire year they were followed. Since clomiphene citrate is not accepted by the FDA for use in men, little information exists regarding the long-term effects of carrying it (including the risk of developing prostate cancer) or if it is more effective at boosting testosterone compared to exogenous formulations. But unlike adrenal gland, clomiphene citrate preserves -- and possibly enhances -- sperm production. This makes drugs like clomiphene citrate one of just a few options for men with low testosterone who want to father children. What kinds of testosterone-replacement treatment can be found? * The earliest form is an injection, which we still use since it is cheap and because we reliably get fantastic testosterone levels in almost everybody. The drawback is that a man should come in every couple of weeks to get a shot. A roller-coaster effect can also happen as blood glucose levels peak and return to research. [Watch"Exogenous vs. endogenous testosterone," above.] Topical therapies help maintain a more uniform level of blood testosterone. The first kind of topical treatment has been a patch, but it has a quite high rate of skin irritation. In 1 study, as many as 40% of men who used the patch developed a red area in their skin. That restricts its usage. The most commonly used testosterone preparation in the United States -- and the one I start almost everyone off -- is a topical gel. According to my experience, it has a tendency to be consumed to great levels in about 80% to 85% of men, but that leaves a substantial number who don't absorb enough for it to have a positive effect. [For specifics on various formulations, see table below.] Are there any drawbacks to using gels? How long does it take for them to work? Men who start using the implants need to return in to have their own testosterone levels measured again to be certain they are absorbing the right amount. Our goal is that the mid to upper assortment of normal, which generally means around 500 to 600 ng/dl. The concentration of testosterone in the blood really goes up quite quickly, within a few doses. I usually measure it after two weeks, even though symptoms may not alter for a month or two. |