WEIGHT LOSS IS ASSOCIATED WITH REDUCED INCIDENCE AND PROGRESSION OF STRUCTURAL DEFECTS IN KNEE OSTEOARTHRITIS, AS ASSESSED BY RADIOGRAPHY OVER 4 TO 5 YEARS: A PROSPECTIVE MULTI-COHORT STUDY
Authors: Salis Z et al., Australia
The aim of this study was to determine the association between change in body mass index (BMI) and the incidence and progression of structural damage in knee osteoarthritis.
Scores from radiographic analyses of knees at baseline and at 4 to 5 years’ follow-up were obtained from three independent data sets (the OAI and MOST data sets from the United States from America, and the CHECK data set from the Netherlands). The exposure of interest was change in BMI from baseline to 4 to 5 years’ follow up. A total of 6084 knees (from 3996 participants) that had a KL grade at baseline of ‘minimal’ (2), ‘moderate’ (3), or ‘severe’ (4) (the ‘progression cohort’) were analysed.
Change in BMI was positively associated with both the incidence and progression of knee osteoarthritis, as defined by KL grade. Change in BMI was also positively associated with degradation (i.e., narrowing) of joint space on the medial but not the lateral side of the knee. Degradation of the tibial and femoral surfaces (i.e., osteophytes) was also seen on the medial but not the lateral side of the knee.
Each one-unit reduction in BMI is associated with a 5 to 8% decrease in the odds of the incidence and progression of the structural defects of knee osteoarthritis, with lower odds of structural degradation specific to the medial, not the lateral side of the knee. Weight reduction is therefore one of the key treatments in the prevention of knee OA and the reduction in progression of existing knee OA.