Diabetes is associated with longitudinal declined physical performance measures in persons with or at risk of knee osteoarthritis: data from the Osteoarthritis Initiative.

Diabetes status was self-reported, which risks misclassification if participants were unaware of their diagnosis. The study did not account for the duration of diabetes, medication use, or family history, which could influence physical performance. Knee osteoarthritis severity was adjusted for using baseline radiographic grades only, not how the arthritis progressed over the eight years. Participants were recruited from specific sites and may not represent those with poor health who declined to participate, limiting generalizability.

The authors declared no conflicts of interest. The study was funded by Prince Sattam Bin Abdulaziz University. The Osteoarthritis Initiative data collection was supported by the National Institutes of Health and private funding partners including Merck, Novartis, GlaxoSmithKline, and Pfizer.

Do not assume diabetes causes the observed decline directly. This is an observational study, so it shows an association between diabetes and faster physical decline in people with knee osteoarthritis, but it does not prove that diabetes is the sole cause or that treating diabetes will reverse the trend.