Women can suffer severe problems, such as osteoporosis, after their reproductive hormones dry up. Now comes new evidence that men, too, tend to fall apart as their blood levels of a sex hormone--in this case, testosterone--drop. Experts say the findings, reported in the current issue of the Proceedings of the National Academy of Sciences, suggest that the time is ripe to study the benefits of hormone replacement therapy for men.
Several studies have shown that elderly men in poor health have abnormally low levels of a hormone called dehydroepiandrosterone (DHEA), a testosterone precursor produced in the adrenal glands. To examine how this hormone and others affect the physical and mental abilities of healthy men as they age, John Morley, a geriatrician at St. Louis University School of Medicine, and his colleagues measured several steroids and hormones in blood serum from 56 healthy men aged 20 to 84. The researchers then performed a battery of cognitive tests, including verbal and nonverbal memory tests, and physical tests for balance and grip strength.
As expected, physical and mental abilities declined over time. Morley's group, however, found that this deterioration appeared to best match decreases in blood levels of the hormone testosterone, although DHEA also correlated more loosely with the declines.
Morley argues that hormone replacement for aging men might have to include testosterone as well as DHEA, which many older American men now get as an over-the-counter drug. "Can we bring up the levels to that of a young adult? Yes," says Eugene Roberts, a neurobiochemist at the Beckman Research Institute in Duarte, California. Other researchers emphasize that a more rigorous study is needed to test the benefits of male-hormone therapy.