EUGENE, Ore. -- (Oct. 25, 2013) -- Twenty grams of essential amino acids taken twice daily for a week before and for two weeks after knee-replacement surgeries helped 16 patients, mean age 69, recover faster and with much less muscle atrophy than a control group ingesting a placebo.
The approach -- detailed in a paper now online ahead of print in the Nov. 13 issue of the Journal of Clinical Investigation -- could spell relief and speed recovery for a growing population of aging adults who face total knee-replacements because of loss of mobility and pain problems. An estimated 3.48 million Americans are projected to need the surgery, known as total knee arthroplasty (TKA), by 2030.
The findings are part of an ongoing collaboration led by Hans C. Dreyer, a professor of human physiology at the University of Oregon, with the Eugene-based Slocum Research & Education Foundation and the Oregon Research Institute.
Atrophy in the quadriceps, a group of four muscles on the front of the thigh, has been a long-running problem following knee-replacement surgeries, Dreyer said.
In the study, 12 members of a control group receiving 40 grams a day of a non-essential amino acid supplement, a placebo, averaged an 18.4 loss in quadriceps muscle mass in their operated leg six weeks after surgery; those getting the supplement of eight essential amino acids (EEA) averaged a 6.2 percent loss. Eighty percent of atrophy occurred in the first two weeks after surgery. Atrophy in non-operative legs was about 50 percent of that in the operative leg in both groups. Muscle mass changes were seen with magnetic resonance imaging done at two and six weeks after surgery.
"We've learned that the essential amino acids were able to mitigate the amount of muscle loss," Dreyer said. "The functional measures that we looked at -- getting up out of a chair, going up a flight of stairs and going back down the stairs -- were all back to baseline in the t
|Contact: Jim Barlow|
University of Oregon