Association between body weight fluctuation and progression of radiographic knee osteoarthritis: a longitudinal cohort study.

Objectives: To investigate the relationship between body weight fluctuation and the progression of knee pain and joint space loss () in people with radiographic knee osteoarthritis (RKOA) during a 48-month follow-up period.

Design: We conducted a longitudinal study using data from the Osteoarthritis Initiative. We analysed body weight variability through metrics of average successive variability (ASV), and residual ASV from baseline to 48 months. We assessed the impact of the fluctuations on changes in the Western Ontario and McMaster Universities Osteoarthritis Index pain scores and JSL, defined as a decrease of ≥0.7 mm in medial joint space width (JSW), using generalised estimating equations to account for correlation within-person and adjusted for covariates.

Results: A total of 2993 and 2789 knees from 2051 participants were included in the pain and JSW analyses, respectively. Higher body weight variability correlated with increased knee pain but not JSL. Participants with high variability (ASV ≥2.07 kg) had a greater OR of aggravated knee pain (OR: 1.24, 95% CI: 1.01 to 1.51, MD: 0.30, 95% CI: 0.05 to 0.54), particularly among initially overweight or obese individuals (OR: 1.30, 95% CI: 1.05 to 1.62, MD: 0.35, 95% CI: 0.08 to 0.62) and those who gained over 3% body weight (OR: 1.54, 95% CI: 1.01 to 2.33, MD: 0.65, 95% CI: 0.16 to 1.14).

Conclusions: Body weight fluctuations are a potential risk factor for symptom progression in RKOA, especially among overweight/obese individuals or those who gain weight. Maintaining a stable body weight may help alleviate the progression of symptoms related to knee osteoarthritis.