It might be said that testosterone is the thing that makes men, 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 regular erections. It also boosts the creation of red blood cells, boosts mood, and aids cognition.
As time passes, the "machinery" which makes testosterone gradually becomes less effective, and testosterone levels begin to drop, by about 1 percent a year, beginning in the 40s. As guys get into their 50s, 60s, and beyond, they might start to have symptoms and signs of low testosterone like lower sex drive and sense of energy, erectile dysfunction, decreased 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 only about 5 percent of these affected receiving treatment.
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 can 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 particular expertise in treating lower testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment strategies he uses with his own patients, and he thinks specialists should rethink the potential connection between testosterone-replacement therapy and prostate cancer.Symptoms Related Site and diagnosis
What signs and symptoms of low testosterone prompt that the typical man to see a doctor?
As a urologist, I tend to observe guys since 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 man who complains of erectile dysfunction must possess his testosterone level checked. Men may experience other symptoms, such as more difficulty achieving an orgasm, less-intense climaxes, a much lesser quantity 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 these symptoms there are, 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, but they are often treatable and reversible by normalizing testosterone levels.
Aren't those the very same symptoms that guys have when they are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are quite a few medications that may lessen sex drive, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the quantity of the ejaculatory fluid, no question. But a reduction in orgasm intensity usually doesn't go together with therapy for BPH. Erectile dysfunction does not usually go along with it either, though surely if a person has less sex drive or less interest, it's more of a struggle to have a fantastic erection.
How do you determine if or not a person is a candidate for testosterone-replacement therapy?
There are two ways 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. Generally men with the lowest testosterone have the most symptoms and guys with maximum testosterone have the least. But there are a number of guys who have low levels of testosterone in their blood and have no signs.
Looking at the biochemical amounts, The Endocrine Society* believes low testosterone to be a total testosterone level of less than 300 ng/dl, and I believe that's a reasonable guide. However, no one really agrees on a number. 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 apparent.
|*Note: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and shouldn't receive testosterone therapy.|
Is complete testosterone the right point to be measuring? Or if we are measuring something else?
This is another area of confusion and good debate, but I don't think that it's as confusing as it appears to be from the literature. When most physicians learned about testosterone in medical school, they learned about overall testosterone, or all the testosterone in the human body. But about half of their testosterone that is circulating in the blood isn't readily available to the cells. It is tightly bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG.
The biologically available portion of total testosterone is known as free testosterone, and it's readily available to cells. Even though it's just a little fraction of this total, the free testosterone level is a fairly good indicator of low testosterone. It is not perfect, but the significance is greater than with testosterone.
Endocrine Society recommendations summarized
This professional organization urges testosterone treatment for men who have both
Therapy is not Suggested for men who have
Do time daily, diet, or other factors influence testosterone levels?
For many years, the recommendation has been to receive a testosterone value early in the morning because levels start to fall after 10 or even 11 a.m.. But the data behind that recommendation were attracted to healthy young men. Two recent studies showed little change in blood glucose 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 modest amount, and probably insufficient 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 doesn't matter much, as long as they obtain their blood drawn before 6 or 5 p.m.
There are a number of rather interesting findings about diet. For example, it seems that those who have a diet low in protein have lower testosterone levels than men who consume more protein. But diet has not been researched thoroughly enough to create any clear recommendations.
Within this guide, testosterone-replacement treatment refers to the treatment of hypogonadism with adrenal gland -- testosterone that is produced outside the body. Based upon the formula, therapy can lead to skin irritation, breast enlargement and tenderness, sleep apnea, acne, reduced sperm count, increased red blood cell count, and other side effects.
In a recent prospective study, 36 hypogonadal men took a daily dose of clomiphene citrate for at least three months. Within four to six weeks, all of the men had heightened levels of testosterone; none reported any side effects during the year they had been followed.
Since 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 is more effective at boosting testosterone than exogenous formulations. But unlike exogenous testosterone, clomiphene citrate preserves -- and possibly enriches -- sperm production. This makes medication such as clomiphene citrate one of just a few choices for men with low testosterone who want to father children.Formulations
What forms of testosterone-replacement therapy can be found? *
The earliest form is the injection, which we still use because it's cheap and since we faithfully become good testosterone levels in nearly everybody. The disadvantage is that a person 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 baseline.
Topical treatments help preserve a more uniform amount of blood testosterone. The first form of topical treatment has been a patch, but it has a very high rate of skin irritation. In 1 study, as many as 40 percent of men who used the patch developed a red area in their skin. That restricts its use.
The most commonly used testosterone preparation from the United States -- and also the one I start almost everyone off -- is a topical gel. The gel comes in miniature tubes or within a unique dispenser, and you rub it on your shoulders or upper arms once a day. Based on my experience, it tends to be consumed to good levels in about 80% to 85% of men, but that leaves a significant number who do not absorb sufficient for this to have a positive impact. [For details on various formulations, see table ]
Are there any downsides to using gels? How much time does it require them to work?
Men who begin using the implants need to come back 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, even although symptoms may not change for a month or two.