A Harvard expert shares his thoughts on testosterone-replacement therapy
An interview with Abraham Morgentaler, M.D.
It could be stated that testosterone is the thing that makes guys, men. It gives them their characteristic deep voices, large muscles, and body and facial hair, differentiating them from women. It stimulates the growth of the genitals , 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 aids cognition.
Over time, the "machinery" which makes testosterone gradually becomes less powerful, and testosterone levels start to fall, by approximately 1% a year, starting in the 40s. As men get into their 50s, 60s, and beyond, they may begin to have signs and symptoms of low testosterone such as reduced sex drive and sense of energy, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and nausea. Taken together, these signs and symptoms are often referred to as hypogonadism ("hypo" meaning low functioning and"gonadism" speaking to the testicles). Researchers estimate that the illness affects anywhere from two to six million men in the United States. Yet it is an underdiagnosed issue, with only about 5 percent of those affected receiving treatment.
But little consensus exists on what constitutes low testosterone, when testosterone supplementation makes sense, or what risks patients face.
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 sexual and reproductive problems. He's developed specific experience in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment strategies he utilizes his own patients, and why he believes specialists should rethink the possible link between testosterone-replacement treatment and prostate cancer.
Symptoms look at this now and Go Here diagnosisWhat signs and symptoms of low testosterone prompt that the average man to find a doctor?
As a urologist, I have a tendency to observe guys because they have sexual complaints. The primary hallmark of reduced testosterone is low sexual libido or desire, but another can be erectile dysfunction, and any guy who complains of erectile dysfunction must get his testosterone level checked. Men can experience different symptoms, such as more trouble achieving an orgasm, less-intense climaxes, a smaller quantity of fluid out of ejaculation, and a feeling of numbness in the manhood when they see or experience something which would normally be arousing.
The more of these symptoms you will find, the more probable 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 same symptoms that men have when they are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are a number of medications which may lessen sex drive, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the amount of the ejaculatory fluid, no question. But a decrease in orgasm intensity usually does not go along with therapy for BPH. Erectile dysfunction does not ordinarily go together with it either, though certainly if somebody has less sex drive or less interest, it is more of a struggle to have a fantastic erection.
How do you determine whether or not a person is a candidate for testosterone-replacement treatment?
There are just two ways that 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 ideal. 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 numbers, The Endocrine Society* believes low testosterone to be a entire testosterone level of less than 300 ng/dl, and I believe that's a reasonable guide. But no one quite agrees on a few. It's not like diabetes, where if your fasting sugar is above 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 should and should not receive testosterone treatment. |
Is total testosterone the right thing to be measuring? Or should we be measuring something different?
This is just another area of confusion and good debate, but I don't think it's as confusing as it appears to be in the literature. When most physicians learned about testosterone in medical school, they heard about overall testosterone, or all of the testosterone in the body. But about half of the testosterone that is circulating in the blood isn't readily available to the cells. It is closely bound to a carrier molecule known as sex hormone--binding globulin, which we abbreviate as SHBG.
The biologically available part of overall testosterone is called free testosterone, and it's readily available to the cells. Though it's just a small fraction of the overall, the free testosterone level is a fairly good indicator of low testosterone. It's not ideal, but the significance is greater compared to total testosterone.
Endocrine Society recommendations outlinedThis professional organization recommends testosterone treatment for men who have both
Therapy Isn't Suggested for men who have
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Do time of day, diet, or other elements influence 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 data behind that 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 this day. One reported no change in average testosterone until after 2 Between 6 and 2 p.m., it went down by 13%, a modest sum, and probably not enough to affect diagnosis. Most guidelines nevertheless say it is important to do the evaluation in the morning, but 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 some 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 researched thoroughly enough to make any clear recommendations.
Exogenous vs. endogenous testosteroneWithin this guide, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that is produced outside the body. Depending upon the formulation, therapy can cause skin irritation, breast tenderness and enlargement, 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 foster the creation of natural testosterone, known as nitric oxide, in men. Within four to six months, each one of the guys had heightened levels of testosterone; none reported some side effects during the year they had been followed. Because clomiphene citrate is not accepted by the FDA for use in men, little information exists about the long-term ramifications of taking it (including the probability of developing prostate cancer) or if it is more capable of boosting testosterone compared to exogenous formulations. But unlike exogenous testosterone, clomiphene citrate maintains -- and possibly enhances -- sperm production. This makes medication like clomiphene citrate one of only a few options for men with low testosterone that want to father children. |
What kinds of testosterone-replacement treatment are available? *
The oldest form is the injection, which we use since it is cheap and because we reliably get fantastic testosterone levels in almost everybody. The disadvantage is that a man 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 baseline. [Watch"Exogenous vs. endogenous testosterone," above.]
Topical treatments help preserve a more uniform amount of blood testosterone. The first form of topical therapy has been a patch, but it has a quite large 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 usage.
The most widely used testosterone preparation in the United States -- and the one I start almost everyone off -- is a topical gel. Based on my experience, it tends to be absorbed to good levels in about 80% to 85 percent of men, but 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 gels have to come back in to have their testosterone levels measured again to be certain they are absorbing the proper quantity. Our goal is that the mid to upper range of normal, which usually means around 500 to 600 ng/dl. The concentration of testosterone in the blood actually goes up quite fast, in just several doses. I normally measure it after two weeks, though symptoms may not change for a month or two.