No causal link between herpes zoster and ischemic stroke: evidence from Mendelian randomization study

The association between herpes zoster (HZ) and stroke has been the subject of much previous research. Nevertheless, the connection remains ambiguous. A two-sample Mendelian randomisation study was conducted to explore the potential causal link between HZ and ischaemic stroke, including its subtypes.

For our MR analysis, we identified genetic instrumental variables related to both HZ and stroke by screening two prominent publicly accessible genome-wide association study databases. The primary approach involved using the inverse variance weighting method. To supplement this, we also employed methods such as MR-Egger regression, the weighted median approach, simple and weighted models. Lastly, to ascertain the stability and reliability of the results, we conducted tests for heterogeneity detection, horizontal pleiotropy assessment, and a leave-one-out analysis.

The genetically predicted HZ did not indicate an association with stroke risk ([OR] 1.041; 95% [CI] 0.958-1.131;p = 0.336). This lack of association also held true for different subtypes of stroke: ischaemic stroke (OR = 1.047, 95% CI = 0.955-1.148, p = 0.323), large vessel stroke (OR = 1.13, 95% CI = 0.90-1.41, p = 0.272), cardioembolic stroke (OR = 1.020, 95% CI = 0.859-1.211, p = 0.816), small vessel stroke (OR = 1.14, 95% CI = 0.93-1.40, p = 0.195), and lacunar stroke (OR = 1.195, 95% CI = 0.967-1.476, p = 0.097).

This MR study showed that not uncover a causal link between herpes zoster and ischaemic stroke. Additional research will be necessary in the future to shed light on the fundamental mechanisms involved.