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, distinguishing them from girls. It stimulates the growth of the genitals , plays a role in sperm production, fuels libido, and contributes 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 start to fall, by approximately 1% a year, starting in the 40s. As men get into their 50s, 60s, and beyond, they might begin to have signs and symptoms of low testosterone like lower sex drive and sense of energy, erectile dysfunction, diminished energy, reduced muscle mass and bone density, and nausea. Taken together, these symptoms and signs are often called hypogonadism ("hypo" meaning low working and"gonadism" speaking to the testicles). Yet it's an underdiagnosed problem, with only about 5 percent of these affected receiving treatment.
But little consensus exists on 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 may stimulate prostate cancer.
He's developed particular expertise in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment plans he utilizes his patients, and why he believes specialists should rethink the possible link between testosterone-replacement therapy and prostate cancer.
Symptoms and diagnosisWhat signs and symptoms of low testosterone prompt the average man to see a physician?
As a urologist, I have a tendency to observe guys since they have sexual complaints. The main hallmark of reduced testosterone is low 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 orgasms, a smaller amount 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 these"soft symptoms" as a normal part of aging, but they are often treatable and reversible by normalizing testosterone levels.
Aren't those the same symptoms that guys have when they are treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are quite a few medications which may reduce libido, including the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the amount of the ejaculatory fluid, no question. 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 a person has less sex drive or less attention, it is more of a struggle to have a good erection.
How do you decide if or not a man is a candidate for testosterone-replacement therapy?
There are just 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 men with the lowest testosterone have the most symptoms and men with highest testosterone possess the least. However, there are some men who have low levels of testosterone in their blood and have no signs.
Looking 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. However, no one quite agrees on a number. It is 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 is not quite as apparent.
| *Notice: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and shouldn't receive testosterone treatment. For a complete copy of the guidelines, log he said on to www.endo-society.org. Is total testosterone the ideal point to be measuring? Or should we be measuring something different? Well, this is another area of confusion and good debate, but I don't think that it's as confusing as it appears to be in 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 readily available to 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 is readily available to the cells. Though it's only a little fraction of this total, the free testosterone level is a fairly good indicator of low testosterone. It is not perfect, but the correlation is greater than with testosterone.
Do time daily, diet, or other factors affect testosterone levels? For many years, the recommendation has been to get a testosterone value early in the morning since levels start to drop after 10 or even 11 a.m.. But the data behind this recommendation were drawn from healthy young men. Two recent studies showed little change in blood glucose levels in men 40 and older 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 modest amount, and probably insufficient to affect diagnosis. Most guidelines still say it's important to perform the evaluation in the morning, but for men 40 and above, it probably does not matter much, provided that they get their blood drawn before 5 or 6 p.m. There are some rather interesting findings about dietary supplements. For example, it appears that those 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.
What kinds of testosterone-replacement treatment can be found? * The earliest form is an 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 occur 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 people that used the patch developed a red area on their skin. That restricts its usage. 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. According to my experience, it has a tendency to be absorbed to good degrees in about 80% to 85 percent of men, but leaves a substantial number who don't consume sufficient for it to have a positive impact. [For details on various formulations, see table below.] Are there any downsides to using dyes? How long does it require them to work? Men who start using the implants need to come back in to have their testosterone levels measured again to be certain they're absorbing the proper amount. Our target is that the mid to upper assortment of normal, which usually means approximately 500 to 600 ng/dl. The concentration of testosterone in the blood really goes up quite fast, within several doses. I normally measure it after two weeks, even though symptoms may not alter for a month or two. |