A Harvard expert shares his thoughts on testosterone-replacement Treatment
It could be stated that testosterone is what makes guys, guys. It gives them their characteristic deep voices, large muscles, and body and facial hair, differentiating them from girls. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and leads to normal erections. It also boosts the production of red blood cells, boosts mood, and aids cognition.
Over time, the testicular"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 might start to have symptoms and signs of low testosterone like reduced sex drive and sense of vitality, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and anemia. Taken together, these signs and symptoms are often referred to as hypogonadism ("hypo" meaning 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 problem, with just about 5 percent of those affected undergoing therapy.
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 diseases and male sexual and reproductive problems. He's developed specific expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his views on current controversies, the treatment strategies he utilizes his patients, and why he thinks specialists should rethink the potential connection between testosterone-replacement treatment and prostate cancer.
Symptoms and diagnosisWhat symptoms and signs of low testosterone prompt the average man to find a physician?
As a urologist, I have a tendency to observe guys since they have sexual complaints. The main hallmark of low testosterone is reduced sexual desire or libido, but another can be erectile dysfunction, and any man 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 climaxes, a smaller amount of fluid from ejaculation, and a feeling 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 that may lessen sex drive, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also reduce the quantity of the ejaculatory fluid, no wonder. However a decrease in orgasm intensity normally does not go along with treatment for BPH. Erectile dysfunction does not usually go along with it , though certainly if somebody has less sex drive or less interest, it's more of a challenge to get a fantastic erection.
How can you decide if or not a man is a candidate for testosterone-replacement therapy?
There are two ways that 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. 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's a sensible guide. However, no one quite agrees on a number. It is not like diabetes, where 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 clear.
| *Note: The Endocrine Society recommends clinical practice guidelines with recommendations for who should and shouldn't receive testosterone treatment. For a complete copy of the look at this web-site guidelines, log on to www.endo-society.org. Is total testosterone the ideal thing to be measuring? Or if we are measuring something else? Well, this is just another area of confusion and great discussion, but I don't think that it's as confusing as it is apparently in the literature. When most physicians learned about testosterone in medical school, they heard about total testosterone, or all the testosterone in the human body. But about half of the testosterone that is circulating in the bloodstream isn't available to cells. The available portion of total testosterone is known as free testosterone, and it's readily available to the cells. Almost every laboratory has a blood test to measure free testosterone. Even though it's just a small fraction of this total, the free testosterone level is a fairly good indicator of low testosterone. It's not ideal, but the correlation is greater compared to total testosterone.
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 since levels start to drop after 10 or even 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 within the course of the day. One reported no change in typical testosterone until after 2 Between 6 and 2 p.m., it went down by 13%, a small sum, and probably not enough to influence identification. Most guidelines nevertheless say it's important to do the evaluation in the morning, however for men 40 and above, it probably doesn't matter much, provided that they obtain their blood drawn before 5 or 6 p.m. There are some very interesting findings about dietary supplements. By way of example, 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. In the following guide, testosterone-replacement treatment refers to the treatment of hypogonadism with exogenous testosterone -- testosterone that is manufactured outside the body. Depending 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 were 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's more capable of boosting testosterone compared to exogenous formulas. But unlike adrenal gland, clomiphene citrate maintains -- and potentially enhances -- sperm production. This makes drugs like clomiphene citrate one of only a few choices for men with low testosterone who want to father children. |
What forms of testosterone-replacement therapy are available? *
The oldest form is an injection, which we use because it's cheap and since we faithfully become fantastic testosterone levels in nearly everybody. The disadvantage is that a man should come in every couple of weeks to find a shot. A roller-coaster effect may also occur as blood testosterone levels peak and return to research.
Topical therapies help maintain a more uniform amount of blood glucose. The first form of topical therapy was a patch, but it has a quite large rate of skin irritation. In one study, as many as 40% of people that used the patch developed a reddish area on their skin. That limits 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 has a tendency to be absorbed to good degrees in about 80% to 85% of men, but leaves a substantial number who do not consume enough for this to have a favorable effect. [For details on several different formulations, see table below.]
Are there any downsides to using gels? How long does it require them to work?
Men who start using the implants need to come back in to have their own testosterone levels measured again to make sure they are absorbing the right amount. Our goal is the mid to upper range of normal, which usually means around 500 to 600 ng/dl. The concentration of testosterone in blood actually goes up quite fast, within several doses. I usually measure it after 2 weeks, even though symptoms may not alter for a month or two.