A population-based nested case-control study in the United States (The Northern Manhattan Study, NOMAS) found no association of serum copeptin with ischemic stroke risk [20]; another hospital-based cross-sectional study reported that plasma copeptin levels in patients with cerebral infarction, intracranial hemorrhage, and subarachnoid hemorrhage were significantly higher than that in healthy volunteers [22]. This evidence concerns the gene AVP and subarachnoid hemorrhage.