Association of residential green space, blue space, and natural environment with osteoarthritis risk: The role of air pollution and phenotypic age acceleration

Over a median follow-up of 12.49 years, 5909 participants developed OA. Within the 300 m buffer, each 5 % increase in green space, blue space, and natural environment was associated with lower OA risk, with hazard ratios (HRs) and 95 % confidence intervals (CIs) of 0.96 (0.95-0.97), 0.95 (0.91-0.99), and 0.98 (0.97-0.99). PAFs indicated that lower levels of green space, blue space and natural environment exposure could be attributed to 9.12 %, 5.15 %, and 9.05 % of OA cases. Meaningful interactions were observed between PM₁₀, NO₂ and the residential environment, with a stronger joint protective effect among individuals with a younger PhenoAge. Mediation analyses indicated notable indirect effects through NO₂ and PM_10. CONCLUSIONS: A higher residential environment was associated with a lower OA risk, with PM₁₀ and NO₂ exhibiting both interaction and mediation roles. Individuals with younger PhenoAge benefited more from these protective effects.