Statin use and pneumonia risk in Parkinson's disease

Introduction: Previous studies reported that statin use was related to a lower risk of pneumonia in the general population. This study investigated the association between statin use and pneumonia risk in patients with Parkinson's disease (PD). Methods: Patients that had been newly diagnosed with PD between 2004 and 2006 in the 2002-2017 National Health Insurance Service database in South Korea were identified. PD patients who had received one or more statin prescriptions, and experienced pneumonia during the observation period were included in the selfcontrolled case series (SCCS) analysis. Patients who had no previous statin prescription record were included in the Cox proportional hazard model with a time-varying covariate (statin use). The risk of pneumonia in PD patients with statin use was estimated after adjusting potential confounders. Results: Of the 10,159 patients with PD, 337 individuals were eligible for the SCCS analysis. The median duration of statin exposure was 2.63 years (IQR, 0.83-5.83). The incidence of pneumonia was reduced in the statinexposed period compared to the unexposed period (incidence rate ratio, 0.88; 95% CI, 0.86-0.91). A total of 8,022 patients were included in the Cox proportional hazard model. Statin use was related to a significantly reduced pneumonia risk (adjusted hazard ratio, 0.69; 95% CI, 0.62-0.78). Conclusions: Statin use was associated with a lower risk of pneumonia in PD patients. Statins might affect pneumonia occurrence by lowering cholesterol levels or slowing the progression of PD as neuroprotective agents. Further clinical studies are needed to delineate our findings with the underlying biological mechanisms.