It could be said that testosterone is what makes guys, guys. It gives them their characteristic deep voices, large muscles, and facial and body hair, differentiating them from girls. It stimulates the growth of the genitals at puberty, plays a role in sperm production, fuels libido, and leads to regular erections. It also boosts 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 in their 50s, 60s, and beyond, they might start to have signs and symptoms of low testosterone like lower libido and sense of vitality, erectile dysfunction, decreased energy, decreased muscle mass and bone density, and anemia. Taken together, these symptoms and signs are often referred to as hypogonadism ("hypo" meaning low working and"gonadism" referring to the testicles). Yet it is an underdiagnosed issue, with only about 5 percent of those affected undergoing therapy.
Various studies have revealed that testosterone-replacement therapy may provide a wide selection of benefits for men with hypogonadism, such as improved libido, mood, cognition, muscle mass, bone density, and red blood cell production. Much of the current debate focuses on the long-held belief that testosterone may 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 has developed particular experience in treating low testosterone levels. In this interview, Dr. Morgentaler shares his perspectives on current controversies, the treatment strategies he utilizes his patients, and he thinks experts should reconsider the potential connection between testosterone-replacement therapy and prostate cancer.Symptoms and diagnosis
What symptoms and signs of low testosterone prompt the typical person to see a physician?
As a urologist, I have a tendency to see guys because they have sexual complaints. The main hallmark of low testosterone is low sexual libido or desire, but another can be erectile dysfunction, and some other guy who complains of erectile dysfunction should get his testosterone level checked. Men can experience other symptoms, such as more trouble achieving an orgasm, less-intense orgasms, a lesser quantity of fluid from 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 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're treated for benign prostatic hyperplasia, or BPH?
Not precisely. There are quite a few drugs that may reduce libido, such as the BPH drugs finasteride (Proscar) and dutasteride (Avodart). Those drugs can also decrease the quantity of the ejaculatory fluid, no wonder. However a reduction in orgasm intensity usually does not go together with therapy for BPH. Erectile dysfunction does not ordinarily go along with it either, though certainly if a person has less sex drive or less attention, it is more of a struggle to get a good erection.
How do you determine if or not a person is a candidate for testosterone-replacement treatment?
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 these two methods is far from perfect. Generally men with the lowest testosterone have the most symptoms and men with highest testosterone have the least. However, there are a number of guys who have reduced levels of testosterone in their blood and have no signs.
Looking at the biochemical numbers, The Endocrine Society* considers low testosterone to be a total testosterone level of less than 300 ng/dl, and I believe that is a sensible guide. However, no one really agrees on a few. It is similar to diabetes, in which if your fasting sugar is over a certain level, they'll say,"Okay, you've got it." With testosterone, that break point is not quite as apparent.
|*Note: The Endocrine Society publishes clinical practice guidelines with recommendations for who should and shouldn't receive testosterone therapy. Watch"Endocrine Society recommendations summarized."|
Is total testosterone the right thing to be measuring? Or should we be measuring something else?
Well, this is another area of confusion and great debate, but I don't think 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 human body. However, about half of their testosterone that is circulating in the blood isn't available to the cells. It's tightly bound to a carrier molecule called sex hormone--binding globulin, which we abbreviate as SHBG.
The biologically available part of overall testosterone is known as free testosterone, and it is readily available to cells. Almost every lab has a blood test to measure free testosterone. Though it's just a little fraction of the total, the free testosterone level is a pretty good indicator of reduced testosterone. It is not perfect, but the correlation is greater than with testosterone.
This professional organization recommends testosterone therapy for men who have
- Low levels of testosterone in the blood (less than 300 ng/dl)
- symptoms of low testosterone.
Therapy is not Suggested for men who've
- Breast or prostate cancer
- a nodule on the prostate that may be felt during a DRE
- that a PSA greater than 3 ng/ml without further evaluation
- that a hematocrit greater than 50% or thick, viscous blood
- untreated obstructive sleep apnea
- severe lower urinary tract symptoms
- class III next or why not try this out IV heart failure.
Do time daily, diet, or other elements affect testosterone levels?
For years, the recommendation was to get a testosterone value early in the morning since levels begin to drop after 10 or even 11 a.m.. However, 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 within the course of this day. One reported no change in average testosterone till after 2 p.m. Between 6 and 2 p.m., it went down by 13%, a small sum, and probably not enough to affect diagnosis. Most guidelines still say it is important to perform the test in the morning, however 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 rather 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 studied thoroughly enough to create any clear recommendations.
Exogenous vs. endogenous testosterone
Within this guide, testosterone-replacement therapy refers to the treatment of hypogonadism with adrenal gland -- testosterone that is produced outside the body. Based on the formula, treatment can lead to skin irritation, breast enlargement and tenderness, sleep apnea, acne, decreased sperm count, increased red blood cell count, and 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, termed nitric oxide, in men. Within four to six months, all the guys had increased levels of testosterone; none reported some side effects during the entire 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 effective at boosting testosterone compared to exogenous formulations. But unlike exogenous testosterone, clomiphene citrate maintains -- and potentially enhances -- sperm production. That makes medication such as clomiphene citrate one of only a few choices for men with low testosterone that wish to father children.
What forms of testosterone-replacement treatment can be found? *
The oldest form is the injection, which we use because it is cheap and because we reliably get fantastic testosterone levels in almost everybody. The disadvantage is that a man should come in every couple of weeks to find a shot. A roller-coaster effect can also occur as blood testosterone levels peak and then return to research. [Watch"Exogenous vs. endogenous testosterone," above.]
Topical treatments help maintain a more uniform level of blood testosterone. The first kind of topical treatment was 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 limits its use.
The most widely used testosterone preparation from the United States -- and also the one I begin almost everyone off -- is a topical gel. The gel comes from miniature tubes or within a unique dispenser, and you rub it on your shoulders or upper arms once a day. According to my experience, it tends to be absorbed to great degrees in about 80% to 85 percent of men, but that leaves a substantial number who do not consume sufficient for this 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 make sure they're absorbing the right amount. Our target is the mid to upper range of normal, which usually means around 500 to 600 ng/dl. The concentration of testosterone in blood really goes up quite quickly, within a few doses. I usually measure it after two weeks, even although symptoms may not alter for a month or two.