Muscle density is the ratio of lean tissue to fat contained within muscle
A study conducted at the California Pacific Medical Center Research Institute indicated that elderly with low muscle density have a higher likelihood of being hospitalized than those with a more moderate ratio and suggests it may be a better predictor of the risk of hospitalization than muscle mass or size
New research suggests exercise programs designed to increase muscle density in the elderly could help reduce rates of disability and hospitalization. Researchers studied 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.
In a study published in the current issue of the Journal of the American Geriatrics Society, 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.
“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.
The team analyzed more than 3,000 healthy seniors aged between 70 and 80 for an average of five years and looked at factors such as their walking speeds, ability to stand up repeatedly and leg strength. They found that the largest number of hospitalizations occurred among those with the least dense muscles.
Dr. Peggy Cawthon, the study’s lead author, says the findings are important because they suggest non-pharmacological and non-surgical approaches such as enhanced physical activity or moderate exercise may help keep vulnerable seniors out of hospital.
A high-protein diet or appropriate supplementation may also be useful for some seniors at risk of low muscle density.
Source for Additional Information:
CEDHD Laet, BA Hout, H Burger, A Hofman, … – British Medical Journal, 1997 – bmj.com
… BMJ 1997;315:221-225 (26 July) Papers. Bone density and risk of hip fracture
in men and women: cross sectional analysis. Chris EDH …
The American Academy of Orthopaedic Surgeons has more about the physical effects of aging.