Dr. Simeon Margolis
Testosterone Replacement in Older Men
by Simeon Margolis
Over the past few years men have been bombarded even more by print and television ads from drug companies selling testosterone gels and creams. These ads describe the problems caused by low testosterone and the benefits of testosterone replacement. This may at least partly account for the increased number of men seeking treatment for low testosterone and the 90 percent increase in testosterone prescriptions over the past five years.
Testosterone levels do fall with age
The ads accurately point out that testosterone levels fall slowly with age. And they suggest that these lower levels may cause such problems as:
- diminished libido (sexual desire)
- erectile dysfunction, and a lower frequency of orgasm
- diminished muscle mass and strength
- loss of bone mineral density
- increased body fat
- depressed mood
- chronic fatigue
However, it's not at all clear whether these changes result only from aging or from the decline in testosterone, especially since they often occur in older men with normal testosterone levels.
Benefits not well established regarding testosterone replacement
The ads may be deceptive when they mention the improvements that will accompany testosterone replacement. While some studies have shown, for example, that testosterone melts body fat and increases muscle mass and strength, others have not. A committee of the Institute of Medicine of the National Academy of Sciences has concluded that there are no well-established beneficial effects of administering testosterone in older men.
Nonetheless, quite low blood levels of testosterone may cause or worsen aging symptoms. The only way to find out is to ask your doctor to measure your blood testosterone. This is best to be done early in the morning with several repeat measures if levels are low, because of limitations in the accuracy of the tests. Many doctors will prescribe testosterone replacements if your levels are consistently less than 300 ng/dL. However, some experts would only prescribe testosterone if blood levels are less than 200 ng/dL.
Adverse effects are possible
There may be adverse effects from taking testosterone. One concern: testosterone replacements may speed the development or progression of prostate cancer. Although this danger is not well documented, a digital rectal exam and PSA test are recommended before starting testosterone. In addition, testosterone may worsen sleep apnea and usually raises red blood cell numbers which heightens the risk of stroke. Also of concern, a 2010 report in the New England Journal of Medicine found that older men (average age 74 years) who took testosterone replacement for six months had a significant increase in the number of heart attacks and strokes; many of them had significant risks for cardiovascular disease.