Effect of statins on Parkinson's disease: A systematic review and meta-analysis

BACKGROUND: Statins have key lipid-lowering, anti-inflammatory, and anti-oxidative effects. However, it remains unclear whether statins are beneficial to patients with Parkinson's disease (PD). This study aimed to evaluate the relationship between statins and PD through a systematic review. METHODS: This study adhered to the guideline of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Potentially relevant case-control or cohort studies published before March 2018 were identified by searching the MEDLINE (PubMed), EMBASE (OVID), CENTRAL (Cochrane Library), CNKI, WANGANG, VIP, CBM, CMCC, Clinicaltrials.gov, ProQuest, Opengray, and ISI Proceedings databases and conducting a manual search. Summarized relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a fixed effect model. Sensitivity and subgroup analyses were also performed. RESULTS: The meta-analysis included 17 studies (3,845,303 patients; 8 case-control and 9 cohort studies), including 5 articles not cited by other studies. We searched the Chinese database, but unfortunately, no Chinese literature can be included in the study. Briefly, statins could decrease the risk of PD, with a summary OR of 0.92 (95% CI: 0.86–0.99). A sensitivity analysis demonstrated the robustness of the results. Subgroup analyses revealed heterogeneity across the studies in terms of subject race, study type, reporting style, quality, statins type, and time for taking statins. CONCLUSION: Our study provides evidence that statins, especially atorvastatin, can reduce the risk of PD. Different time of statins using has different effects on PD. However, additional randomized controlled trials and observational studies are needed to confirm this conclusion. REGISTRATION ID: PROSPERO CRD: 42018095580