Statins as potential disease-modifying therapy of Parkinson's disease: a systematic review and meta-analysis with trial sequential analysis

Background: Recent evidence indicates that statins have anti-inflammatory and antioxidant effects, leading to several investigations of whether statins have a neuroprotective effect and may benefit patients with Parkinson's disease (PD). However, the potential mechanisms of this class of medications as modifiers of the course of PD in already diagnosed patients is still unclear.

Objectives: To assess the effectiveness of statins as modifiers of established PD.

Methods: Two investigators systematically searched for randomized clinical trials and observational studies comparing PD patients treated with statins versus those treated without statins. The search was conducted in PubMed, Embase, Cochrane, and Web of Science. The outcome of interest was the change in the MDS-UPDRS III (Movement Disorder society-Unified Parkinson's Disease Rating Scale Part III) and UPDRS III scores from baseline. Statistical analysis was performed using R Studio 4.3.2.

Results: Four studies, totaling 472 patients, were included. The standardized mean difference for the MDS-UPDRS Part III and UPDRS Part III scales between statin and non-statin groups was - 0.13 (95% CI - 0.44 to 0.17; p = 0.39; I² = 58%), and there was no statistical significant difference regarding this outcome.

Conclusion: There was no statistical significance for the potential clinical benefit of statins as modifiers of the disease course in PD patients.