Influence of smoking on cerebral circulation in patients with aneurysmal subarachnoid hemorrhage / 中华神经医学杂志

ABSTRACT

Objective To study the effect ofT-786C polymorphism of endothelial NO synthase gene on cerebral circulation in smokers with aneurysmal subarachnoid hemorrhage. Methods Three hundred and ninety-four patients with aneurysmal subarachnoid hemorrhage were adopted in our study;smokers and nonsmokers were defined by 200 and 0, respectively, according to the smoking index (quantity of cigarettes per year). Transcranial color-coded Doppler (TCCD) was employed to detect the alterations of flow velocity of cerebral arteries. Genotyping ofT-786C was performed by using a newly developed allele-specific polymerase chain reaction. Degree of oxidative stress of these patients were evaluated by measuring the level of F2-isoprostane excretion in the urine. Results The mean flow velocity (Vm) of middle cerebral artery (MCA) and internal carotid artery (ICA) was obviously increased as compared with that of the other normal ones in most of the smokers. The Vm of MCA and ICA in nonsmokers was not obviously different as compared with the normal values. The 3 genotypes ofT-786C in smokers showed significant difference in Vm of MCA and ICA (P＜0.05); the Vm of CC genotype ([60.73±63.58] cm/s) was obviously increased as compared with that of TT ([95.8±53.5] cm/s) and TC ([93.6±51.6] cm/s) genotypes (P＜0.05). The 3 genotypes ofT-786C in nonsmokers did not show significant difference in Vm of MCA and ICA (P＞0.05). The level of F2-isoprostane excretion in smokers was significantly higher than that in nonsmokers (P＜0.05). Conclusion The T-786C polymorphism of endothelial NO synthase gene can increase cerebrovascular Vm by enhancing the cerebrovascular circulation of smokers with aneurysmal subarachnoid hemorrhage.