Changes in systemic inflammatory markers may mediate the effects of diet control and exercise on pain, and to a greater extent, on function in overweight and obese patients with knee osteoarthritis (OA), according to a study published in Osteoarthritis and Cartilage.
Researchers analyzed data from the Arthritis, Diet, and Activity Promotion Trial (ADAPT) to assess the effects of cytokine levels on pain and function outcomes following diet restriction and exercise in overweight and obese patients with OA. Participants (n=99) were selected based on the availability of cytokine and clinical outcomes data, which were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index over an 18-month period. The individual effects of various inflammatory factors were evaluated using a mediation analysis model.
Changes in inflammatory factors following diet restriction and exercise were found to account for 15% of the effect on pain levels (medium-size effect, ≥ 13%) and for 29% of the effect on function (strong mediator, ≥26%).
Study limitations include the small sample size.
“These results highlight the relevance of changes in systemic inflammation as drivers for clinically relevant effects after diet and exercise in overweight and obese individuals with knee OA,” the researchers noted.
Runhaar J, Beavers DP, Miller GD, et al. Inflammatory cytokines mediate the effects of diet and exercise on pain and function in knee osteoarthritis independent of BMI [published online April 20, 2019]. Osteoarthritis Cartilage. doi: 10.1016/j.joca.2019.04.009