To investigate whether patients with osteoarthritis (OA) are at a higher risk of developing Parkinson's disease (PD).
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-hazard regression analysis was employed to estimate the effect of having OA on patients' subsequent risk of PD.
Of the two groups, the OA group had a significantly higher risk of developing PD (adjusted hazard ratio [aHR]=1.41, 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 (aHR 1.55, 95% CI, 1.14-2.11) than patients with non-knee and non-hip OA (aHR 1.42, 95% CI, 1.06-1.89) or with uncategorized OA (aHR 1.32, 95% CI,1.05-1.64).
Our findings suggest that OA is linked to an increased risk of developing PD.