A Harvard expert shares his Ideas on testosterone-replacement therapy
It might be said that testosterone is what makes guys, 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. Additionally, it fosters the production of red blood cells, boosts mood, and aids cognition.
Over time, the testicular"machinery" which produces testosterone gradually becomes less effective, and testosterone levels start to drop, by about 1 percent a year, starting in the 40s. As guys get into their 50s, 60s, and beyond, they may begin to have symptoms and signs of low testosterone like lower sex drive and sense of energy, erectile dysfunction, diminished energy, decreased muscle mass and bone density, and anemia. 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 just about 5% of those affected receiving treatment.
Much of the current debate focuses on the long-held belief that testosterone can stimulate prostate cancer.
He's developed particular expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he utilizes his patients, and why he believes experts should reconsider the possible link between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt that the typical man to find a doctor?
As a urologist, I tend to see guys since they have sexual complaints. The primary hallmark of low testosterone is reduced sexual desire or libido, but another may be erectile dysfunction, and any man who complains of erectile dysfunction should possess his testosterone level checked. Men can experience other symptoms, such as more difficulty achieving an orgasm, less-intense orgasms, a smaller quantity of fluid out of ejaculation, and a feeling of numbness in the penis when they see or experience something that would usually be arousing.
The more of the 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 are often treatable and reversible by decreasing testosterone levels.
Are not those the very 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 drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also reduce the quantity of the ejaculatory fluid, no question. However a decrease in orgasm intensity usually doesn't go along with treatment for BPH. Erectile dysfunction does not usually go together with it , though certainly if somebody has less sex drive or less attention, it's more of a challenge to have a fantastic erection.
How can you decide if a person is a candidate for testosterone-replacement therapy?
There are just two ways that we determine whether someone has low testosterone. One is a blood test and the other one is by characteristic signs and symptoms, and the correlation between those two approaches is far from ideal. Generally guys with the lowest testosterone have the most symptoms and guys with highest testosterone possess the least. However, there are a number of guys who have reduced 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 is a reasonable guide. But no one quite agrees on a few. It's similar to diabetes, where if your fasting glucose is over 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 receive testosterone therapy. Watch"Endocrine Society useful reference recommendations summarized." For a complete copy of these guidelines, log on to company website www.endo-society.org. |
Is total testosterone the right point to be measuring? Or should we be measuring something different?
This is another area of confusion and good debate, but I don't think it's as confusing as it is apparently from the literature. When most doctors learned about testosterone in medical school, they heard about total testosterone, or all the testosterone in the body. However, about half of their testosterone that's circulating in the bloodstream is not readily available to cells.
The available part of total testosterone is called free testosterone, and it is readily available to the cells. Nearly every laboratory has a blood test to measure free testosterone. Even though it's only a little portion of this total, the free testosterone level is a pretty good indicator of reduced testosterone. It is not perfect, but the correlation is greater compared to testosterone.
Endocrine Society recommendations summarizedThis professional organization recommends testosterone therapy for men who have Therapy Isn't Suggested for men who've
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Do time daily, diet, or other elements affect testosterone levels?
For years, the recommendation has been to receive a testosterone value early in the morning because levels start to drop after 10 or even 11 a.m.. However, the information behind this recommendation were attracted to healthy young men. Two recent studies showed little change in blood testosterone 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 affect diagnosis. Most guidelines nevertheless say it is important to do the test in the morning, but for men 40 and over, it probably doesn't matter much, as long as they get their blood drawn before 6 or 5 p.m.
There are a number of very interesting findings about diet. By way of example, it seems that individuals who have a diet low in protein have lower testosterone levels than men who eat more protein. But diet hasn't been studied thoroughly enough to make any recommendations that are clear.
Exogenous vs. endogenous testosteroneWithin this guide, testosterone-replacement treatment refers to the treatment of hypogonadism with adrenal gland -- testosterone that's manufactured outside the body. Depending upon the formula, therapy can lead to skin irritation, breast tenderness and enlargement, sleep apnea, acne, decreased sperm count, increased red blood cell count, along with additional side effects. Preliminary research has proven that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, can foster the creation of natural testosterone, also known as nitric oxide, in men. Within four to six months, each one of the men had heightened levels of testosterone; none reported some side effects during the entire year they were followed. Because clomiphene citrate is not accepted by the FDA for use in men, little information exists about the long-term ramifications of carrying it (including the risk of developing prostate cancer) or whether it is more effective at boosting testosterone than exogenous formulas. But unlike exogenous testosterone, clomiphene citrate preserves -- and potentially enriches -- sperm production. This makes drugs such as clomiphene citrate one of just a few options for men with low testosterone who wish to father children. |
What kinds of testosterone-replacement therapy can be found? *
The earliest form is an injection, which we still use because it is inexpensive and because we faithfully become good testosterone levels in nearly everybody. The drawback is that a person should come in every few weeks to find a shot. A roller-coaster effect can also happen as blood testosterone levels peak and return to research.
Topical treatments help preserve a more uniform amount of blood glucose. The first form of topical treatment has been a patch, but it has a quite large rate of skin irritation. In one study, as many as 40% of men who used the patch developed a red area in their skin. That restricts its usage.
The most widely used testosterone preparation from the United States -- and the one I start almost everyone off with -- is a topical gel. There are two brands: AndroGel and Testim. The gel comes in tiny tubes or within a special dispenser, and you rub it on your shoulders or upper arms once a day. Based on my experience, it has a tendency to be absorbed to good levels in about 80% to 85 percent of guys, but that leaves a significant number who don't consume enough for it to have a favorable impact. [For details on various formulations, see table ]
Are there any drawbacks to using gels? How much time does it take for them to work?
Men who begin using the gels have to return in to have their own testosterone levels measured again to be sure they are absorbing the right quantity. Our target is that the mid to upper range of normal, which generally means around 500 to 600 ng/dl. The concentration of testosterone in blood actually goes up quite fast, in just a few doses. I usually measure it after 2 weeks, although symptoms may not alter for a month or two.