Surprising study finds men also benefit from "female" hormone replacement
In a surprising new study, researchers have discovered that estrogen, typically known as a “female” hormone, is a lot more important to men than many doctors even realized.
According to the study, published Wednesday in the New England Journal of Medicine, it’s actually a lack of estrogen in men that’s a problem, as a lack of estrogen is primarily responsible for the build up of body fat in men with low testosterone. This, in turn, results in an increased risk of developing cardiovascular disease and diabetes.
A lack of estrogen is also a primary cause of sexual dysfunction, while low testosterone is usually responsible for low sex drive – and when testosterone drops, so does estrogen. In addition, the researchers from Massachusetts General Hospital in Boston found that low testosterone is linked to a decline in lean muscle mass, muscle size and strength.
These findings could lead to more physicians prescribing hormones for men, similar to the kind of hormone therapy doctors already use to treat menopausal women. And, like postmenopausal women, men with low estrogen also experience a weakening of their bones.
“As men age, they also experience a dwindling of hormones, especially testosterone,” says Michele Zormeier, M.D., an Indiana physician not associated with the study. She says that hormone therapy can “restore the loss of energy and vitality that some experience as part of the aging process”, adding that hormone replacement also helps improve sleep and libido.
“I’ve seen dramatic results in patients (on hormone therapy), not just in their physical health, but in their marriages and relationships in general,” Dr. Zormeier said.
Hormone therapy in men has already jumped considerably, despite concerns over potential side effects. According to a study published this year in JAMA Internal Medicine, the approximate number of American men over 40 receiving testosterone has tripled from 2001 to 2011.
Around the age of 35, when testosterone and estrogen start to drop, one of the first symptoms experienced is often a decreased libido, followed by an accumulation of fat as estrogen levels further decline. Lastly, when testosterone drops to very low levels, a loss of muscle mass and strength is typically seen.
Of course, not everyone experiences the same drop in hormone levels. While a normal range for testosterone is between 300 and 1,000 nanograms per deciliter of blood (based on the average levels found in the general population), researchers involved in this latest study report that a healthy range should really depend upon the individual body tissue or system.
Dr. Zormeier utilizes a variety of blood, urine, and saliva tests to determine individual hormone levels. Depending on the results, she then creates a customized treatment plan that usually involves a combination of hormone creams.
“Depending on the individual and their test results, I sometimes prescribe additional testosterone because it can help increase estrogen levels,” she explained.
For the study, 400 healthy men 20 to 50 years old were all given a drug to stop production of testosterone, as well as estrogen. They ere then divided into two groups, with one group receiving a placebo and the other group receiving an actual testosterone replacement product.
The men in the other group were given the same replacement dosages, but also a drug to inhibit aromatase, so their bodies would make almost no estrogen.
Over a period of 16 weeks, the research team then tracked how the men physically reacted by using body scans, surveys, and strength tests.
In the men receiving an actual testosterone replacement product where estrogen production was blocked, there was a significant rise in body fat, as well as an increase in erectile dysfunction and low sexual desire.
“When you lose estrogen, it’s all bad,” said endocrinologist Joel Finkelstein, who led the study. “With estrogen loss you get fat accumulation, loss of libido, bone loss.”
Finkelstein also pointed out that the effects of estrogen loss are associated with osteoporosis, diabetes, cardiovascular disease, and the burgeoning debate over routinely prescribing testosterone to older men to increase both testosterone and estrogen levels as part of preventive medicine.
“What do we do about men as they age into their 60s, 70s, 80s? Is it helpful or harmful? Both? Neither? We don’t know,” Finkelstein said.
In the meantime, the researchers from Massachusetts General Hospital plan to find out by repeating the study with older men.
SOURCE: New England Journal of Medicine, Gonadal Steroids and Body Composition, Strength, and Sexual Function in Men (September 12, 2013), Joel S. Finkelstein, M.D., et al. (N Engl J Med 2013; 369:1011-1022) DOI: 10.1056/NEJMoa1206168