原发性高血压及高血压合并高胆固醇血症血管内皮功能的超声研究

目的 探讨原发性高血压及高血压合并高胆固醇血症患者血管内皮依赖性舒张功能的改变。方法 采用彩色多普勒高频超声的间歇成像和能量多普勒成像，对24例原发性高血压患者（EH组）、24例高血压合并高胆固醇血症患者（EH＋HC组）及24例正常血压、血胆固醇者（NT组）的血管内皮依赖性舒张功能，包括静息时血管内径（BD）、增加流量引起的血管舒张（FMD）、服用硝酸甘油引起的血管舒张（GTN）等，以及对血浆一氧化氮（NO）、内皮素（ET）、血栓素B2（TXB2）和前列腺环素（PGI2）等血管活性物质进行检测并比较分析。结果 EH和EH＋HC组反应性充血引起的FMD值明显减弱，与NT组比较差异有非常显著性（均P〈0．01），EH与EH＋HC组之间比较差异亦有统计学意义（P〈0．05）；含服硝酸甘油后肱动脉内径明显扩张，但各组间GTN值差异无统计学意义（P〉0．05）；EH＋HC、EH组与NT组比较血浆中NO、PGI2水平明显降低，而ET、TXB2水平明显升高（均P〈0．01），EH＋HC与EH组间比较差异亦有统计学意义（P〈0．05）。结论 高血压患者存在血管内皮依赖性舒张功能受损，高血压合并高胆固醇血症时，内皮功能受损进一步加重。彩色多普勒超声是评价血管内皮舒张功能的简单、无创且可靠方法。

Evaluation of vascular endothelial function in patients with hypertension or hypertension complicated with hypercholesterolemia via color Doppler flow imaging

Objective To assess the endothelium-dependent dilation in patients with hypertension or hypertension complicated with hypercholesterolemia via color Doppler flow imaging (CDFI). Methods With high frequency ultrasound intermittent imaging and power Doppler imaging, we evaluated endothelium-dependent relaxing function in 72 subjects. Of them, 24 had essential hypertension (EH), 24 had hypertension complicated with hypercholesterolemia (EH+HC) and the rest 24 were normal controls. We measured the diameter of the superficial femoral and brachial arteries at rest, during reactive hyperemia, re-test and after sublingual glyceryl trinitrate (GTN) for evaluating the endothelium-independent dilatation in these subjects. The levels of plasma NO, ET, PGI_2, and TXB_2 were determined and compared among the 3 groups.Results There were significant decrease in flow-mediated dilatation in EH and EH+HC groups than in normal controls (P<0.01 for both). The difference of decreased flow-mediated dilatation was also significant between EH+HC and EH groups (P<0.05). By contrast, dilatation of brachial artery diameter due to GTN did not differ among the 3 groups (P<0.05). The concentrations of plasma NO and PGI_2 in EH and EH+HC groups were significantly lower than those in normal controls (P<0.01 for both). The concentrations of plasma ET and TXB_2 were significantly higher in EH and EH+HC groups than in normal controls (P<0.01 for both). In addition, the differences of above-mentioned parameters were also significant between EH and EH+HC groups (P<0.05). Conclusions Endothelium-dependent dilation was impaired in patients with hypertension. The degree of the impairment was more serious in patients with hypertension and hypercholesterolemia. Color Doppler ultrasound image can be successfully used in assessing endothelium-dependent dilation. It is a simple, non-invasive and reliable technique.