Association between Apolipoprotein E Polymorphism and Clinical Outcome after Ischemic Stroke, Intracerebral Hemorrhage, and Subarachnoid Hemorrhage

Backgrounds: Previous studies reported inconsistent results regarding associations between apolipoprotein E (APOE) polymorphism and clinical outcomes after ischemic stroke (IS), intracerebral hemorrhage (ICH), or subarachnoid hemorrhage (SAH). Thus, the study was designed to make a systematic review and meta-analysis regarding the association between APOE polymorphism and clinical outcome after IS, ICH, and SAH. Methods: To identify studies eligible for this meta-analysis, we searched for articles published before August 2021 in the databases (PubMed, Web of Science, and Google Scholar). We used STATA 12.0 software to compute hazard ratios (HRs) and their 95% confidence intervals (CIs) regarding APOE polymorphism and clinical outcome after IS, ICH, and SAH. Results: Meta-analysis showed no significant association between APOE polymorphism and functional outcome after IS with fixed effects models ( e 4 carrier vs. non- e 4 carrier: HR, 1.00; 95% CI: 0.83-1.21, I-2 = 29.4%, p = 0.183; e 2 carrier vs. non- e 2 carrier: HR, 0.92; 95% CI: 0.72-1.16, I-2 = 15.6%, p = 0.307). Meta-analysis showed that ICH patients carrying e 4 allele have increased risk of poor outcome in Caucasian population with fixed effects models ( e 4 carrier vs. non- e 4 carrier: HR, 1.75; 95% CI: 1.19-2.57, I-2 = 0.0%, p = 0.543). Meta-analysis showed no significant association between APOE polymorphism and functional outcomes after SAH with random effects models ( e 4 carrier vs. non- e 4 carrier: HR, 1.51; 95% CI: 0.80-2.84, I-2 = 57.1%, p = 0.022). Conclusions: In conclusion, the present study demonstrated APOE e 4 carriers show worse functional outcomes after ICH, but not after IS or SAH. More large-scale studies were critical to explore the association between APOE polymorphism and clinical outcome after IS, ICH, and SAH. (C) 2021 S. Karger AG, Basel.

Automated summary

The study found that APOE e 4 carriers showed worse functional outcomes after intracerebral hemorrhage, but not after ischemic stroke or subarachnoid hemorrhage. Further large-scale studies are needed to explore the association between APOE polymorphism and clinical outcomes after ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage.