A Harvard expert shares his Ideas on testosterone-replacement Treatment
A meeting with Abraham Morgentaler, M.D.
It could be said that testosterone is the thing that makes men, guys. It gives them their characteristic deep voices, large muscles, and body and facial hair, differentiating them from women. It stimulates the development of the genitals at puberty, plays a role in sperm production, fuels libido, and leads to regular erections. It also boosts the production of red blood cells, boosts mood, and aids cognition.
As time passes, the testicular"machinery" which produces testosterone gradually becomes less powerful, and testosterone levels begin to fall, by approximately 1 percent 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 like lower sex drive and sense of energy, erectile dysfunction, decreased energy, reduced muscle mass and bone density, and nausea. Taken together, these signs and symptoms are often referred to as hypogonadism ("hypo" significance low functioning and"gonadism" referring 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 just about 5% of those affected undergoing therapy.
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.
He's developed specific expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment plans he utilizes his patients, and why he thinks specialists should rethink the possible link between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt that the typical man to see a doctor?
As a urologist, I tend to see men 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 guy who complains of erectile dysfunction should get his testosterone level checked. Men may experience other symptoms, such as more difficulty achieving an orgasm, less-intense orgasms, a lesser quantity of fluid out of ejaculation, and a sense of numbness in the manhood when they see or experience something which would usually be arousing.
The more of the symptoms you will find, the more probable it is that a man has low testosterone. Many physicians often discount those"soft symptoms" as a normal part of aging, however, they're often treatable and reversible by normalizing testosterone levels.
Aren't those the same symptoms that men have when they're treated for benign prostatic hyperplasia, or BPH?
Not exactly. There are a number of drugs which may lessen sex drive, including the BPH medication finasteride (Proscar) and dutasteride (Avodart). Those drugs may also reduce the quantity of the ejaculatory fluid, no wonder. But a reduction 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 attention, it is more of a struggle to get a good erection.
How do you decide if or not a man is a candidate for testosterone-replacement therapy?
There are two ways we determine whether somebody has reduced 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 ideal. Normally guys with the lowest testosterone have the most symptoms and men with highest testosterone possess the least. However, there are some men who have reduced levels of testosterone in their blood and have no signs.
Looking purely at the biochemical numbers, The Endocrine Society* believes low testosterone for a total testosterone level of less than 300 ng/dl, and I think that is a sensible guide. But no one really agrees on a few. It is not like diabetes, in which 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 clear.
| *Notice: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and shouldn't receive testosterone treatment. |
Is complete testosterone the right thing to be measuring? Or if we are measuring something different?
Well, this is just another area of confusion and good debate, but I do not think 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 body. However, about half of the testosterone that is circulating in the blood is not available to cells.
The available portion of total testosterone is known as free testosterone, and it's readily available to cells. Almost every laboratory has a blood test to measure free testosterone. Even though it's just a small portion of the overall, the free testosterone level is a pretty good indicator of reduced testosterone. It's not ideal, but the significance is greater than with total testosterone.
This professional organization urges testosterone therapy for men who have
- Reduced levels of testosterone in the blood (less than 300 ng/dl)
- symptoms of low testosterone.
Therapy is not recommended for men who've
- Prostate or breast cancer
- a nodule on the prostate that may be felt during a DRE
- a PSA higher than 3 ng/ml without additional evaluation
- that a hematocrit greater than 50% or thick, viscous blood
- untreated obstructive sleep apnea
- severe lower urinary tract infections
- class III or important source IV heart failure.
Do time of day, 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 fall after 10 or 11 a.m.. But the information 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 typical testosterone until after 2 p.m. Between 6 and 2 p.m., it went down by 13 percent, a small amount, and probably insufficient to influence identification. Most guidelines still say it is important to perform the test in the morning, but for men 40 and above, it likely does not matter much, as long as they get their blood drawn before 5 or 6 p.m.
There are a number of rather interesting findings about diet. For instance, it appears that individuals that have a diet low in protein have lower testosterone levels than males who eat more protein. But diet hasn't been studied thoroughly enough to make any recommendations that are clear.
FormulationsExogenous vs. endogenous testosterone
Within the following guide, testosterone-replacement therapy refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that is produced outside the body. Based upon the formula, therapy can cause skin irritation, breast enlargement and tenderness, sleep apnea, acne, reduced sperm count, increased red blood cell count, along with additional side effects.
Within four to six months, each one the guys had increased levels of testosteronenone reported any side effects during the year they were followed.
Because clomiphene citrate is not approved by the FDA for use in men, little information exists about the long-term effects of taking it (including the risk of developing prostate cancer) or whether it is more capable of boosting testosterone compared to exogenous formulations. But unlike exogenous testosterone, clomiphene citrate preserves -- and possibly enhances -- sperm production. That makes medication such as clomiphene citrate one of just a few options for men with low testosterone that wish to father children.
What forms of testosterone-replacement therapy are available? *
The oldest form is the injection, which we use because it's inexpensive and because we faithfully become fantastic testosterone levels in nearly 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.
Topical treatments help preserve a more uniform level of blood testosterone. The first kind 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 in the United States -- and also the one I begin almost everyone off with -- is a topical gel. There are two brands: AndroGel and Testim. The gel comes in tiny tubes or in a special dispenser, and you rub it on your shoulders or upper arms once a day. According to my experience, it has a tendency to be absorbed to good degrees in about 80% to 85% of men, but that leaves a significant number who don't consume enough for it to have a favorable impact. [For specifics on several different formulations, see table ]
Are there any drawbacks to using dyes? How long does it take for them to get the job done?
Men who start using the implants need to return in to have their testosterone levels measured again to be certain they are absorbing the right quantity. Our goal is the mid to upper assortment of normal, which generally means around 500 to 600 ng/dl. The concentration of testosterone in blood actually goes up quite fast, within a few doses. I usually measure it after 2 weeks, though symptoms may not alter for a month or two.