A Harvard expert shares his Ideas on testosterone-replacement therapy
A meeting with Abraham Morgentaler, M.D.
It might be said that testosterone is what makes guys, guys. It gives them their characteristic deep voices, big muscles, and body and facial hair, distinguishing them from women. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and leads to regular erections. Additionally, it boosts the creation of red blood cells, boosts mood, and assists cognition.
As time passes, the testicular"machinery" that makes testosterone gradually becomes less effective, and testosterone levels begin to drop, by about 1% 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 such as reduced libido and sense of energy, erectile dysfunction, diminished energy, decreased muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often called hypogonadism ("hypo" significance low functioning and"gonadism" referring to the testicles). Researchers estimate that the condition affects anywhere from two to six million men in the United States. Yet it's an underdiagnosed issue, with just about 5 percent of these affected receiving treatment.
He has developed particular expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment strategies he uses with his own patients, and he believes experts should reconsider the potential connection between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt the typical man to see a doctor?
As a urologist, I have a tendency to see men since they have sexual complaints. The main hallmark of reduced testosterone is low sexual desire or libido, but another may be erectile dysfunction, and some other guy who complains of erectile dysfunction should possess his testosterone level checked. Men may experience different symptoms, like more trouble achieving an orgasm, less-intense orgasms, a much lesser amount of fluid from ejaculation, and a sense of numbness in the penis when they see or experience something which would normally 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 discount those"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 are treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are quite a few drugs that may reduce libido, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the amount of the ejaculatory fluid, no wonder. However a reduction in orgasm intensity usually does not go along with therapy for BPH. Erectile dysfunction does not usually go along with it , though surely if a person has less sex drive or less interest, it is more of a challenge to get a good erection.
How can you determine whether a man is a candidate for testosterone-replacement therapy?
There are just two ways we determine whether somebody has low testosterone. One is a blood test and the other is by characteristic symptoms and signs, and the correlation between these two approaches is far from perfect. Generally guys with the lowest testosterone have the most symptoms and men 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 at the biochemical numbers, The Endocrine Society* believes low testosterone for 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 few. It's not like diabetes, in which if your fasting sugar 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 with recommendations for who should and Find Out More should not receive testosterone therapy. See"Endocrine Society recommendations summarized." For a complete copy of these instructions, log on to www.endo-society.org. Is total testosterone the right thing to be measuring? Or if we are measuring something else? This is just another area of confusion and good discussion, but I do not think that it's as confusing as it appears to be in the literature. When most doctors learned about testosterone in medical school, they learned about total testosterone, or all the testosterone in the body. But about half of the testosterone that is circulating in the blood is not 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 part of total testosterone is called free testosterone, and it is readily available to cells. Nearly every lab has a blood test to measure free testosterone. Even though it's only a small portion of this overall, the free testosterone level is a fairly good indicator of reduced testosterone. It's not perfect, but the significance is greater than with testosterone.
Do time daily, diet, or other factors influence testosterone levels? For 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 information behind that recommendation were drawn from healthy young men. Two recent studies demonstrated little change in blood testosterone levels in men 40 and mature over the course of this day. One reported no change in average testosterone till after 2 Between 2 and 6 p.m., it went down by 13 percent, a modest sum, and probably not enough to affect identification. Most guidelines still say it's important to perform the evaluation in the morning, however 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 some rather interesting findings about dietary supplements. For example, it appears that those 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 clear recommendations. In the following guide, testosterone-replacement therapy refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that is manufactured outside the body. Based upon the formulation, treatment can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, reduced sperm count, increased red blood cell count, and additional side effects. Preliminary research has proven that clomiphene citrate (Clomid), a drug generally prescribed to stimulate ovulation in women struggling with infertility, may foster the creation of natural testosterone, termed nitric oxide, in men. 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 increased levels of testosteronenone reported any side effects during the entire year they were followed. Since clomiphene citrate isn't approved by the FDA for use in males, little information exists regarding the long-term effects of taking it (such as the risk of developing prostate cancer) or whether it's more capable of boosting testosterone compared to exogenous formulations. But unlike exogenous testosterone, clomiphene citrate maintains -- and potentially enhances -- sperm production. That makes medication like clomiphene citrate one of only a few choices for men with low testosterone that want to father children. What forms of testosterone-replacement treatment can be found? * The earliest form is the injection, which we still use since it's cheap and because we faithfully get fantastic testosterone levels in almost everybody. The disadvantage is that a man needs to come in every couple of weeks to get a shot. A roller-coaster effect can also occur as blood testosterone levels peak and return to baseline. Topical treatments 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 one study, as many as 40 percent of people that used the patch developed a reddish area in their skin. That restricts its usage. The most widely used testosterone preparation in the United States -- and also the one I begin almost everyone off with -- is a topical gel. There are just two brands: AndroGel and Testim. According to my experience, it tends to be absorbed to great levels in about 80% to 85 percent of men, but leaves a significant number who do not consume enough for it to have a favorable effect. [For specifics on various formulations, see table below.] Are there any downsides to using dyes? How much time does it take for them to get the job done? Men who start using the gels have to return in to have their testosterone levels measured again to be certain they're absorbing the proper quantity. Our target is 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 fast, in just a few doses. I normally measure it after 2 weeks, even although symptoms may not change for a month or two. |