WFU study: moderate weight loss takes major pressure off the knee
By Maggie Barrett
Moderate weight loss substantially reduces pressure on the knees of overweight and obese adults suffering from osteoarthritis of the knee, according to new research from Wake Forest University published in the July issue of "Arthritis & Rheumatism."
Stephen Messier, professor of health and exercise science at Wake Forest, was principal investigator for the study. His goal was to identify the specific correlation between weight loss and the amount of stress placed on the knee while walking.
One hundred and forty-two overweight and obese older adults with osteoarthritis of the knee participated in the study. The participants followed an 18-month weight loss program, resulting in an average body weight loss of two percent.
When Messier and his fellow researchers measured the load placed on the knees after weight loss, they discovered that every pound lost netted a 4-pound reduction in pressure exerted on the knees. With every step taken, the amount of pressure not exerted on the knees begins to add up.
"For people losing 10 pounds, each knee would be subjected to 48,000 pounds less in comprehensive load per mile walked," Messier wrote in the study article.
Messier says there are no studies showing that weight loss slows the progression of osteoarthritis of the knee, but that the discovery of the 4-pound pressure reduction for every pound lost warrants research into that area and holds promise for treating and perhaps preventing the disease.
Messier and his colleagues were inspired to conduct this study by the results of a prior Wake Forest University study published in May 2004. Called ADAPT (Arthritis, Diet and Activity Promotion Trial), the study Ð for which Messier was also the principal investigator Ð confirmed the efficacy of moderate weight loss achieved through a combination of diet and exercise as a treatment for osteoarthritis of the knee. ADAPT received national recognition from the Arthritis Foundation as one of the top 10 arthritis advances of 2004.
Osteoarthritis, the leading cause of disability in the United States, destroys the cartilage tissue that acts like shock absorbers in the joints. The result is pain, stiffness and eventual loss of mobility in the joint or joints affected. Obesity is the most important, modifiable risk factor associated with osteoarthritis of the knee.