Body weight changes and corresponding changes in pain and function in persons with symptomatic knee osteoarthritis. A cohort study

Riddle DL et al. – The data suggest a dose–response relationship exists between changes in body weight and corresponding changes in pain and function. The threshold for this response gradient appears to be ≥10% body weight shifts. Weight changes of ≥10% have potential to lead to important changes in pain and function for patient groups as well as individual patients.

Methods

• Data from persons in the Osteoarthritis Initiative (OAI) and the Multicenter Osteoarthritis (MOST) datasets (n=1,410) with symptomatic function limiting knee OA were studied.
• For the OAI, the authors used baseline and 3–year follow–up data while for the MOST, baseline and 30–month data were used. Key outcome variables were WOMAC Physical Function and Pain change scores.
• In addition to covariates, the predictor variable of interest was the extent of weight change over the study period and divided into 5 categories representing different percentages of body weight change.

Results

• A significant dose–response relationship (p< 0.003) was found between the extent of percentage change in body weight and the extent of change in WOMAC Physical Function and WOMAC Pain.
• For example, persons who gained ≥10% of body weight had WOMAC Physical Function score changes of –5.4 (95%CI, –8.7, –2.00) points indicating worsening relative to the reference group of persons with weight changes of between <5% weight gain and <5% weight reduction.

[more...]