Kullo Iftikhar J, Malik A Rauoof, Santos Simone, Ehrsam Jo-Ellen, Turner Stephen T
Division of Cardiovascular Diseases, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
Am J Hypertens. 2007 Jul;20(7):735-42. doi: 10.1016/j.amjhyper.2007.01.015.
Alterations in microvascular and conduit artery function contribute to target organ damage in hypertension. We investigated the association of cardiovascular (CV) risk factors with microvascular and conduit artery function in hypertensive subjects.
Participants included 504 hypertensives (aged 62.1 +/- 9.8 years, 42% men) from the community, without history of symptomatic CV disease. Brachial artery ultrasound was performed to measure forearm blood flow (FBF) at rest and during reactive hyperemia (markers of microvascular function) and flow-mediated dilatation (FMD) of the brachial artery (a marker of conduit artery endothelial function). The association of conventional and novel (homocysteine, C-reactive protein, fibrinogen, and lipoprotein a CV risk factors with microvascular function and FMD was tested in multivariable regression models.
Variables independently associated with higher resting FBF were male sex, higher body mass index (BMI), smoking, and lower HDL-cholesterol; variables associated with lower hyperemic FBF included greater age, female sex, and diabetes. Higher plasma homocysteine was associated with lower hyperemic FBF in obese subjects (P for log homocysteine x BMI interaction = .0008). Variables independently associated with lower FMD were greater age, sex gender, history of smoking, and not using statins. Higher homocysteine was associated with lower FMD in subjects with higher systolic blood pressure (P for interaction = .0004). Hyperemic flow velocity was independently associated with FMD (P = .0006), but its inclusion as a covariate did not influence the association of CV risk factors with FMD.
In asymptomatic subjects with essential hypertension, select CV risk factors were associated with microvascular and conduit artery function. Furthermore, the association of CV risk factors with conduit artery function appeared to be independent of downstream microvascular function.
微血管和传导动脉功能改变会导致高血压患者的靶器官损害。我们研究了高血压患者心血管（CV）危险因素与微血管和传导动脉功能之间的关联。
研究对象包括504名来自社区的高血压患者（年龄62.1±9.8岁，42%为男性），无有症状的心血管疾病史。采用肱动脉超声测量静息状态下和反应性充血时的前臂血流量（FBF）（微血管功能指标）以及肱动脉的血流介导的扩张（FMD）（传导动脉内皮功能指标）。在多变量回归模型中测试了传统和新型（同型半胱氨酸、C反应蛋白、纤维蛋白原和脂蛋白a）CV危险因素与微血管功能和FMD之间的关联。
与较高静息FBF独立相关的变量包括男性、较高的体重指数（BMI）、吸烟和较低的高密度脂蛋白胆固醇；与较低充血性FBF相关的变量包括年龄较大、女性和糖尿病。在肥胖受试者中，较高的血浆同型半胱氨酸与较低的充血性FBF相关（对数同型半胱氨酸×BMI交互作用的P值=0.0008）。与较低FMD独立相关的变量包括年龄较大、女性、吸烟史和未使用他汀类药物。在收缩压较高的受试者中，较高的同型半胱氨酸与较低的FMD相关（交互作用的P值=0.0004）。充血血流速度与FMD独立相关（P=0.0006），但将其作为协变量纳入并未影响CV危险因素与FMD之间的关联。
在无症状原发性高血压患者中，特定的CV危险因素与微血管和传导动脉功能相关。此外，CV危险因素与传导动脉功能之间的关联似乎独立于下游微血管功能。
