Johns Hopkins professor Adrian Dobs, M.D. talks about testosterone replacement therapy.
After age 40, a man’s testosterone level declines by about 1% each year. Most men don’t experience symptoms. But if the testosterone level drops below 300 nanograms per deciliter (ng/dL), as measured by a blood test, this indicates a condition called hypogonadism that can only be treated with testosterone therapy.
The symptoms of hypogonadism may sound like common age-related concerns: decreased sex drive, fatigue, forgetfulness, or weakness. “Many men may simply think these declines are normal,” says Adrian Dobs, M.D., Professor of Medicine and Oncology in the Division of Endocrinology and Metabolism at Johns Hopkins, “but these are not necessarily inevitable symptoms of aging.” Men experiencing these so-called age-related symptoms should talk to their doctors. In some instances, these troubles may be the result of low hormone levels and testosterone therapy can help.
Testosterone – A Fountain of Youth?
Since boosting testosterone improves the symptoms of hypogonadism, you’re not alone if you wondered if it could help keep you young and vigorous, even if your hormone levels are normal for your age. Internet advertisements for testosterone therapy abound, as do books promoting it as an anti-aging serum, and testosterone prescriptions have increased by 500% since 1993. Testosterone therapy also has been touted to help conditions such as Alzheimer’s and heart disease.
One of its most alluring promises is an increased sex drive. Dr. Dobs states, “Healthy men are more likely to have more active sex lives and have higher testosterone levels.” In men with hypogonadism, testosterone replacement can improve libido and erectile function. However, if your hormone levels are normal, adding testosterone will not be helpful. Rather, it may result in a decline in your natural testosterone production. If you have lost interest in sex or have trouble maintaining an erection, there are many treatments you might consider and you should discuss these with your doctor.
Testosterone does build muscle: You’ve probably read in the news about professional athletes’ illegal steroid use of testosterone injections. Although testosterone therapy can be helpful for hypogonadal men, using it to build muscle if your hormone levels are normal can be dangerous. Impotence, liver disease, heart attack, and stroke are some of the more serious consequences of testosterone abuse.
Testosterone – A Weapon Against Disease
Several studies have found that men who develop Alzheimer’s disease also have lower testosterone levels, but research into treating Alzheimer’s with testosterone therapy has been disappointing. Dr. Dobs observes, “One problem may be that testosterone is converted into estrogen in the brain and some data say estrogen makes dementia worse. It’s too early to say whether or not testosterone therapy can alter the course of Alzheimer’s disease.”
Higher testosterone levels have long been cited as the reason more men than women have heart attacks—and estrogen seems to protect women against heart disease, at least before menopause. But an emerging body of evidence suggests low testosterone levels increase a man’s risk of heart disease. Several studies have looked at testosterone replacement to treat men with angina and heart failure. Remarks Dr. Dobs, “Overall, the effect of testosterone therapy on heart disease may be neutral. There is little evidence that boosting testosterone helps the heart and in high doses it might even be dangerous because it lowers HDL (‘good’) cholesterol.” Fortunately, there are many effective ways of treating heart disease and its risk factors.
Interestingly, many chronic diseases such as diabetes and some types of cancer are associated with a decline in testosterone levels. It is unclear if the testosterone level affects the disease. But the drop in hormones may contribute to a poorer quality of life. Men with diabetes, cancer, or other chronic diseases should have a blood test done to determine their hormone levels.
Testosterone and Prostate Cancer Controversy
One of the most controversial uses of testosterone therapy is in men with a history of prostate cancer. While there is no evidence that testosterone therapy causes prostate cancer, it does fuel tumor growth in men who have the disease. Dr. Dobs explains, “Some controversy has arisen over whether or not men who are considered cured of prostate cancer can use testosterone if they find that, down the road, their hormone levels drop below normal.”
Dr. Dobs says that most experts would still recommend that men with a history of prostate cancer not be treated with testosterone therapy. But in rare situations, hormone therapy might be considered: If hormone levels are low and symptoms of hypogonadism are apparent, if several years have passed since diagnosis, if the tumor was low risk and treated with surgery, and if tests reveal no further evidence of disease. “In general,” cautions Dr. Dobs, “after much discussion with his doctor, any man who decides to try hormone replacement therapy should be carefully monitored for prostate cancer with regularly scheduled prostate specific antigen (PSA) testing and digital rectal exams.”
The Bottom Line on Testosterone Therapy
There is increasing evidence that testosterone therapy may help sexual dysfunction associated with hypogonadism, and the association between testosterone and mental function remains an important avenue of research. Testosterone therapy won’t restore youthful vigor. But don’t assume that feeling run down, uninterested in sex, or forgetful is normal. Talk to your doctor to find out if your hormone levels are low or if there is another way to address your problems.
