Association of Osteoarthritis With Increased Risk of Parkinson's Disease: A Population-Based, Longitudinal Follow-Up Study.

ABSTRACT

OBJECTIVE: To investigate whether patients with osteoarthritis (OA) are at a higher risk of developing Parkinson's disease (PD). METHODS: This retrospective cohort study was conducted using Taiwan's Longitudinal Health Insurance Database 2005. We enrolled 33,360 patients who were 50-64 years old and had OA in 2002-2005 to form the OA group. The comparison group consisted of 33,360 age- and sex-matched, randomly sampled subjects without OA. Then, their PD-free survival curves were generated using the Kaplan-Meier method. Multivariable Cox proportional hazards regression analysis was employed to estimate the effect of having OA on patients' subsequent risk of PD. RESULTS: Of the 2 groups, the OA group had a significantly higher risk of developing PD (adjusted hazard ratio [HRadj ] 1.41 [95% confidence interval (95% CI) 1.16-1.70], P = 0.0003). The PD-free survival rate of the OA group was also significantly lower than that of the comparison group (P = 0.0004). The subgroup analysis showed that patients with knee or hip OA appeared to have a higher magnitude of PD risk (HRadj 1.55 [95% CI 1.14-2.11]) than patients with non-knee and non-hip OA (HRadj 1.42 [95% CI 1.06-1.89]) or with uncategorized OA (HRadj 1.32 [95% CI 1.05-1.64]). CONCLUSION: Our findings suggest that OA is linked to an increased risk of developing PD.