Association between Hypertension and the Risk of Parkinson’s Disease: A Meta-Analysis of Analytical Studies

BACKGROUND: The results of analytical studies show that the association between hypertension and the risk of Parkinson's disease (PD) remains controversial. METHOD: We searched studies related to the association between hypertension and the risk of PD. We pooled the ORs and risk ratios (RRs) with 95% confidence interval (CI) with random effects model and conducted meta-regression to explore potential sources of heterogeneity. Publication bias was estimated by Egger's test and the funnel plot. RESULTS: Twenty-six articles containing 27 studies were included, involving 9 cohort studies and 18 case-control studies. In cohort studies, compared with the non-hypertension participants, the pooled RR for the risk of PD was 1.70 (95% CI 1.60-1.80) for the patients with hypertension. In case-control studies, compared with the non-hypertension participants, the pooled OR for the risk of PD was 0.85 (95% CI 0.78-0.92) for the patients with hypertension. There were no publication bias in cohort studies and case-control studies. CONCLUSION: Based on population-based cohort studies, this meta-analysis indicated that hypertension might increase the risk of PD. In view of both hypertension and PD having an association with aging, case-control studies, especially the studies based on hospital records, were not suitable for similar studies.