Apr 25 (ANI): A new study has found that though extended bed rest, though often necessary during hospitalization, leads to a substantial amount of muscle deterioration in older adults.

The study was conducted by researchers at the University of Arkansas for Medical Sciences (UAMS) who studied the rate of muscle loss in 12 adults with an average age of 67 over 10 days.

They found that the muscle loss was not only more remarkable period than a previous study of younger adults, but also occurred in a shorter.

The research team was led by William J. Evans, Ph.D., director of the Nutrition, Metabolism and Exercise Laboratory in the Donald W. Reynolds Institute on Aging at UAMS.

“We found a dramatic reduction in muscle protein synthesis brought on by inactivity that caused the muscle loss. This is a striking loss of muscle in healthy individuals. When you consider the chronically ill facing longer hospitalizations or bed rest, the magnitude of muscle loss is extraordinary and should be treated,” said Evans.

The 12 study participants, described as moderately active prior to the study, remained in bed continuously for 10 days. During that time, they consumed a diet with the recommended daily allowance of protein (0.8 g/kg per day).

Measurements taken before and after bed rest included the muscle protein synthesis rate over the course of 24 hours, lean body mass, urinalysis and a leg-strength test. Protein synthesis rate drives the increase or reduction in muscle mass, as protein in muscle cells is always being created or broken down, when the rate decreases, more protein is being broken down than created, causing muscle loss.

According to the study, there was a 30 percent decrease in the rate of protein synthesis in muscle cells between the measurements taken before and after the 10 days of bed rest. The researchers also found the bed rest likely caused an increase in insulin resistance, which further ratcheted down the protein synthesis rate.

Muscle mass was measured as a change in lean body mass. The study reported an average 1.5 kg reduction in whole body lean mass and 0.95 kg loss in leg lean mass after bed rest.

The researchers noted that the older adult participants in the UAMS study experienced more muscle loss in 10 days than did younger participants after 28 days as reported in a 2004 article in the Journal of Clinical Endocrinology Metabolism. In that study, an average loss of less than 0.4 kg in leg lean mass was reported after 28 days bed rest in subjects with an average age of 38.

The team plan to continue their research to examine different strategies for preventing muscle loss. Those potential treatments included nutritional supplements, exercise and the use of insulin sensitizers to prevent the reduction in muscle protein synthesis.

The findings appear in the April 25 issue of the Journal of the American Medical Association. (ANI)