Johns Hopkins scientists studying testosterone-replacement therapy report that the primary male sex hormone may affect some learning skills, including improving visual and perceptual abilities. The findings may provide additional insight into testosterone's role in the brain.

"This is an interesting, early finding and it highlights the importance of studying the effects of sex hormones on brain function," says Adrian Dobs, M.D., senior author and an associate professor of medicine.

Results of the study, funded by the National Institutes of Health, will be presented June 14 at the International Congress of Endocrinology's annual meeting in San Francisco. Ten men with low testosterone underwent word, memory, coordination and other learning tests while on and off testosterone treatment. When receiving testosterone, they had improved visual and spatial skills and a better "mental grasp of objects" -- fitting building blocks into the correct spaces, identifying pictures and remembering shapes, patterns and locations, the results showed. When not receiving testosterone, the men showed improved verbal fluency and verbal memory -- making up sentences, defining words and recalling words from a test.

Researchers at Hopkins and elsewhere are studying whether testosterone-replacement therapy may improve men's muscle mass and strength, bone density, cholesterol level, sense of well-being, cognitive function and balance.

"Compared to estrogen research, we're 15 years behind in investigating the benefits of testosterone," says Dobs.

Testosterone replacement therapy has been shown to improve sexual function in men with low testosterone, while many studies suggest that estrogen replacement therapy reduces the risk of heart disease and osteoporosis in women after menopause. It is unclear whether estrogen replacement therapy increases the risk of breast cancer. Hopkins scientists also are investigating whether estrogen has a role in brain function, including
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Contact: John Cramer
jcramer@welchlink.welch.jhu.edu
410-955-1534
Johns Hopkins Medical Institutions
14-Jun-1996