Abstract
BACKGROUND: There is still a lack of knowledge about the relationship between metabolic syndrome (MetS) and Parkinson's disease (PD). This study aimed to determine whether MetS increases PD risk. METHODS: To identify relevant clinical studies, databases such as PubMed, Embase, and the Cochrane Library were searched in depth from the inception of databases until March 31, 2024. The study evaluated the correlation between MetS and the likelihood of developing PD through the computation of aggregated relative risks (RR) and their respective 95% confidence intervals (CIs) utilizing selnRR and lnRR. RESULTS: Seven studies were included in our systematic review. The meta-analysis revealed that patients with MetS have a 0.3-fold increased risk of developing PD (p = 0.001). Furthermore, the analysis revealed a positive correlation between central obesity and the incidence of PD, with an RR of 1.19 (95% CI, 1.16-1.22; p = 0.001), as well as a greater risk of PD in patients with elevated blood pressure, with an RR of 1.13 (95% CI, 1.07-1.19; p = 0.001); elevated serum triglyceride levels, with an RR of 1.09 (95% CI, 1.02-1.15; p = 0.001); lower serum HDL cholesterol levels, with an RR of 1.21 (95% CI, 1.15-1.28; p = 0.001); and elevated plasma fasting glucose levels, with an RR of 1.18 (95% CI, 1.11-1.26; p = 0.001). CONCLUSION: MetS can contribute to the incidence of Parkinson's disease, with individual components of MetS demonstrating comparable effects.