10% Weight Loss May Relieve Arthritic Knee Pain
Biggest improvement seen with diet-exercise combo in 18-month study of older, overweight adults
By Dennis Thompson
TUESDAY, Sept. 24 (HealthDay News) -- Older people with a weight problem can relieve knee pain from osteoarthritis if they lose just 10 percent of their body weight through diet and exercise, a new study finds.
Overweight and obese people 55 or older who participated in a diet and exercise program reported less pain, better knee function, improved mobility and enhanced quality of life when they dropped one-tenth of their weight, according to the study in the Sept. 25 Journal of the American Medical Association.
"We've had a 162 percent increase in knee replacements over the last 20 years in people 65 and over, at a cost of $5 billion a year," said lead author Stephen Messier. "From our standpoint, we think this would be at least a good way to delay knee replacements and possibly prevent some knee replacements."
The 18-month study followed up on earlier findings that showed a 5 percent weight loss decreased knee pain and increased function in older folks, said Messier, a professor and director of the J.B. Snow Biomechanics Laboratory at Wake Forest University.
"We thought, well, 5 percent did great -- what if we did more?" he said. "Would a more intense weight loss prompt more improvement on clinical outcomes?"
The study included 454 overweight and obese people who were suffering pain from diagnosed knee osteoarthritis. They were randomly assigned to one of three groups -- diet-only, exercise-only, and diet and exercise combined.
Participants were put on a thrice-weekly exercise program that included two 15-minute walking sessions separated by a 20-minute strength-training session.
"The whole thing took an hour, including warm-up and cool-down," Messier said. "It wasn't anything super, that no one else could do. We think we got these results through very practical means."
The dietary restrictions proved more intense. Researchers restricted participants to around 1,100 to 1,200 calories per day. They were fed up to two meal-replacement shakes per day of 300 calories each and a balanced dinner that contained between 500 and 750 calories, Messier said.