Statin use and knee osteoarthritis outcomes: a longitudinal cohort study

Objective: Statins have several pleiotropic effects, but the literature regarding the possible relationship between statins use and outcomes in knee osteoarthritis (OA) is limited. We investigated whether statins use is associated with lower risk of radiographic (ROA), radiographic symptomatic knee OA (SxOA) and pain in North American people. Methods: A total of 4,448 community-dwelling adults from the Osteoarthritis Initiative were followed-up for 4 years. Statins use (including the time from baseline and the type) was defined through self-report information and confirmed by a trained interviewer. Knee OA outcomes included incident (1) ROA, (2) SxOA, as the new onset of a combination of a painful knee and ROA, (3) knee pain worsening, i.e. a Western Ontario and McMaster Universities Osteoarthritis Index difference between baseline and each annual exam ≥14%. Results: At baseline, 1,127 participants (=25.3%) used statins. Based on a multivariable Poisson regression analysis with robust variance estimators, any statins use was not associated with lower risk of pain worsening (relative risk, RR=0.97; 95%CI, confidence intervals: 0.93-1.02), incident ROA or SxOA. However, statins use > 5 years (RR=0.91; 95%CI: 0.83-0.997) and atorvastatin use (RR=0.95; 95%CI: 0.91-0.996) were associated with a reduced risk of developing pain, whilst rosuvastatin to a higher risk (RR=1.18; 95%CI: 1.12-1.24). The adjustment for the propensity score confirmed these findings. Conclusion: The effect of statins use on knee OA outcomes remains unclear, although in our study those using statins for over five years and those using atorvastatin reported a significant lower risk of developing knee pain.