β2-adrenergic receptor gene polymorphisms and risk of ischemic stroke

Background β2-adrenergic receptors (β2-AR) mediate vasorelaxation in response to adrenergic agents. Genetic polymorphisms of β2-AR were implicated in various cardiovascular and noncardiovascular traits. Methods We tested the role of the β2AR-16 and β2AR-27 gene variants in the susceptibility to the development of ischemic stroke in a genetically homogenous and clinically well-characterized case-control sample that included 294 cases and 286 controls from Sardinia, Italy. This population was shown to be an optimal study sample for carrying out genetic analyses. Results Age, hypertension, dyslipidemia, and atrial fibrillation were independent risk factors for stroke in this cohort. We found that the presence of the Glu27 allelic variant was associated with a significantly increased risk of stroke when assuming a recessive mode of inheritance (odds ratio [OR], 1.68; 95% confidence interval [CI], 1.17–2.41; P = .005). The same results were obtained for the subgroup of ischemic strokes of arterial origin ( n = 215): OR, 1.71; 95% CI, 1.14–2.57; P = .009. Furthermore, haplotype analysis confirmed that the presence of the Glu27 allele increased the risk of cerebrovascular accidents. Conclusions Our data suggest that the Glu27 allelic variant of the β2-AR gene may be a determinant of ischemic stroke.