There has been a lot of talk lately about how low testosterone levels impact a man's health. Hypogonadism - Low T - is when men have a testosterone level below 300. The normal level is anywhere between 300 and 1,200. Men's bodies reduce testosterone production beginning around age 30 and continue to slow down at the rate of about 1 percent per year.
Treating Low Testosterone
Low T has been associated with higher levels of fat in the abdomen, loss of muscle mass, reduced strength, depression, low sex drive and low energy. Increasing the level of testosterone usually results in increased energy and sex drive among other things. Treating Low T is surrounded by controversy. Some doctors are concerned that the long-term effects of increasing testosterone haven't been studied enough, the risks may outweigh the benefits and that we are treating a natural part of aging. Others believe that improving men's quality of life will improve overall health.
The Link Between Testosterone and Estrogen
A new study, however, shows that it may not be low levels of testosterone that are causing medical problems but low levels of estrogen. Estrogen? Isn't that a woman's hormone? Yes, estrogen is considered a female hormone and low levels of estrogen have been linked to osteoporosis, a disease that weakens the bones and increases the risk of sudden and unexpected fractures. Low estrogen can lead to osteoporosis in men as well, however, women are four times more likely than men to develop osteoporosis.
Just as women have low levels of testosterone, men have estrogen. Most of the estrogen in men, however, comes from testosterone. About 80 percent of the estrogen in the male body comes from converting testosterone into estrogen. Therefore, men with lower levels of testosterone also have lower levels of estrogen.
The recent study, completed at Massachusetts General Hospital, looked at how testosterone and estrogen levels impacted men's health. All of the participants - 400 men between the ages of 20 and 50 years old - were given a drug to stop testosterone and estrogen production. The men were then divided into two groups and then each group was divided again into two groups:
- In one group some of the men received testosterone replacement therapy and others received a placebo.
- In the second group men also received replacement therapy but also received a drug to stop production of estrogen
The men who received testosterone, but had estrogen blocked, "showed significant increases in three key body fat measures as well as erectile dysfunction and low sexual drive."  .
Treatment for Low Estrogen in Men
Interestingly, whether the cause is from low testosterone or low estrogen the treatment is the same. Because men produce estrogen by converting their testosterone, increasing this also increases estrogen levels.
Questions about treatment still remain. The risks of treatment include increased risk for heart disease and prostate cancer. Side effects of testosterone replacement therapy can include acne, enlarged breasts, testicle shrinkage and reduced sperm production. Researchers also point out that hormone replacement therapy in women comes with health risks and those risks may be present for men as well.
On the other hand, researchers said prescribing testosterone to older men in order to increase sex function and lower fat accumulation, overall health and quality of life may improve.
 "Men Need 'Female' Hormone for Sex Drive, Fat Control: Study," 2013, Sept. 11, Brian Alexander, NBCNews.com
"Menopause and Osteoporosis," 2011, Staff Writer, Cleveland Clinic