"Considering that side effects often limit the use of drug therapy and surgical intervention is often ineffective for mild or moderate knee osteoarthritis, our results give strong support to the combination of exercise and weight loss as a cornerstone for the treatment of overweight osteoarthritis patients," said Stephen Messier, professor of health and exercise science and principal investigator of the study.
Researchers from Wake Forest's health and exercise science department and Wake Forest University Baptist Medical Center teamed for the study, called ADAPT (Arthritis, Diet and Activity Promotion Trial). They found that participants in an 18-month program of exercise and calorie-restricted diet had a 24 percent improvement in physical function. Participants in this group also reported the most significant improvements in knee pain--a decrease of more than 30 percent.
"Our study supports modest weight loss and moderate exercise as a safe, effective therapy for osteoarthritis of the knee," said Dr. Marco Pahor, professor of gerontology in the Wake Forest School of Medicine at Wake Forest Baptist Medical Center and a co- researcher on the study. Pahor is director of the Claude D. Pepper Older Americans Independence Center of Wake Forest University.
Arthritis is the leading cause of physical disability in adults, affecting more than 70 million Americans. Marked by joint damage and chronic pain, osteoarthritis is the most common form of arthritis. Messier said problems with current treatments--anti-inflammatory drugs with potentially serious long-term side effects and surgery that can be ineffective--present a need for an alternative therapy.
ADAPT measured improvement in physical function, pain and mobility in 252 randomized participants, all age 60 or older, who were overweight, sedentary and had knee pain or knee osteoarthritis. The participants were divided into one of four groups: exercise only, dietary weight loss only, dietary weight loss plus exercise, and the control group called healthy lifestyle.
The exercise group did aerobic and resistance activities for one hour, three times a week. The diet group attended regular meetings on changing their eating habits and reducing calories in their diets. The combination group, where the most improvement was measured, participated in both programs. The healthy lifestyle group attended classes on weight loss and exercise, but did not participate in the programs.
"We suggest that the combination of diet plus exercise produces consistently better and clinically relevant improvements in physical function compared with diet or exercise alone," Messier said.
ADAPT was paid for by a grant from the National Institute of Aging as part of the Pepper Center of Wake Forest University.
MEDIA NOTE: Contact Messier, ADAPT principal investigator, at 336-758-5849, messier@wfu.edu, or through Sarah Mansell at 336-758-5237, manselss@wfu.edu. Contact the medical school through Karen Richardson at Wake Forest Baptist Medical Center, 336-716-4587, krchrdsn@wfubmc.edu.
Journal
Arthritis & Rheumatism