Muscle Density Linked to Disability

02 aug 2009-- Exercise programs designed to increase muscle density in the elderly could help reduce rates of disability and hospitalization, new research suggests.

The contention stems from a study of 3,011 healthy U.S. residents, aged 70 to 80. During about a five-year span, more than 55 percent of them were hospitalized at least once. People most likely to be hospitalized were those who scored lowest on measures of physical function, such as walking speed, ability to stand up from a chair repeatedly, grip strength and leg strength.

The researchers also found that people with the least dense thigh muscles -- meaning more fat than lean tissue -- were more likely to be hospitalized than those with more dense thigh muscles.

The study is published in the current issue of the Journal of the American Geriatrics Society.

"Our research suggests that we need to re-think the way we define sarcopenia, or age-related muscle loss," study author Peggy Cawthon, a scientist with the California Pacific Medical Center Research Institute, said in a news release from the American Geriatrics Society. "Many definitions of sarcopenia today tend to focus on lean mass or muscle size. Our study shows that is looking at the wrong factors. We found that muscle strength or performance were much better ways of measuring function."

The findings "suggest that interventions, such as physical exercise, that improve physical function could help keep more vulnerable seniors out of the hospital," she said. "That would not only reduce disability but it would also reduce the huge economic burden associated with hospitalization of the elderly."

One in five Americans older than 65 has sarcopenia. In 2000, the direct costs of treating the condition were more than $18.5 billion, according to background information in the news release.

More information

The American Academy of Orthopaedic Surgeons has more about the physical effects of aging.