Interrelationship between PQ exposure and Parkinson disease: A systematic review and meta-analysis

Some studies have conflicting findings, suggesting that PQ has no association with the progression of Parkinson disease (PD). This meta-analysis aimed to investigate the impact of PQ on the incidence of PD.

A computerized search was conducted in Pubmed, Embase, Cochrane, Web of Science, and Scopus for literature on factors influencing DEACMP from their inception to October 2023. Statistical analyses and meta-analyses were performed using STATA 17.0 and RevMan 5.4 software, respectively.

A total of 181 articles were retrieved. 14 articles were included, comprising 4731 PD cases and 205,129 control cases. In case-control studies, the proportion of PQ exposure in the PD group was relatively high, with an odds ratio (OR) of 1.47 (95% confidence interval [CI]: 1.25, 1.72; I2 = 2%, P < .00001). In cohort studies, the PD group showed a relatively high proportion of PQ exposure, with an OR of 0.81 (95% CI: 0.71-0.92; I2 = 0%, P = .001). Additionally, subgroup analyses were conducted based on the study area. Studies from the United States and Canada indicated that the proportion of PQ exposure in the PD group was relatively high, with an OR of 1.36 (95% CI: 1.12-1.67; I2 = 10%, P = .002). In addition, the occupational exposure analysis showed that the proportion of PQ exposure in the PD group was higher, with an OR of 0.83 (95% CI: 0.71-0.99; I2 = 10%, P = .03). The environmental exposure analysis indicated a tendency towards a higher proportion of PQ exposure in the PD group, with an OR of 2.37 (95% CI: 0.98-5.73; I2 = 9%, P = .06). The mixed exposure analysis revealed a significantly higher proportion of PQ exposure in the PD group, with an OR of 1.47 (95% CI: 1.25-1.73; I2 = 0%, P < .0001).

This study demonstrates that PQ exposure does not obviously increase the incidence of PD. However, factors such as gender, exposure conditions, and regional differences may affect the incidence of PD induced by PQ exposure. Further clarification is required regarding the impact of paraquat exposure on PD. Simultaneously, efforts should be made to prohibit or reduce the use of and exposure to paraquat.