Risk of Stroke in Patients with Herpes Zoster: A Systematic Review and Meta-Analysis

Background: Several observational studies suggest that herpes zoster (HZ) may increase the risk of stroke, but the results are inconsistent. Our study was designed to assess the association between HZ and the risk of stroke through a meta-analysis of cohort studies. Methods: The electronic databases PubMed and EMBASE were searched from inception to May 31, 2016 to identify relevant cohort studies that assess the risk of stroke in patients with HZ. Reference lists were also reviewed to identify potential studies. The random-effects model and fixed-effects model were used to calculate the summary relative risks (RRs) with 95% confidence intervals (CIs). Results: Six cohort studies (251,076 HZ patients and 8462 cases of stroke) were identified in the study. The result showed that HZ was significantly correlated with increased risk of stroke, and the pooled RR was 1.36 (95% confidence interval [CI]: 1.10, 1.67) (P = .004). In the subgroup analysis, the significant association was observed except for stroke type (hemorrhage group). In the sensitivity analysis, excluding 1 study, the pooled RR was 1.45 (95% CI: 1.17, 1.80) (P = .001) for HZ, and 4.42 (95% CI: 2.75, 7.11) (P = .000) for herpes zoster ophthalmicus. Considerable heterogeneity was observed in our study. Conclusion: Our study furnishes evidence of a positive association between HZ and the risk of stroke.