Carallo C, Irace C, Pujia A, De Franceschi M S, Crescenzo A, Motti C, Cortese C, Mattioli P L, Gnasso A
Dipartimento di Medicina Sperimentale e Clinica "G. Salvatore," Centro Aterosclerosi, University of Catanzaro, Rome, Italy.
Hypertension. 1999 Aug;34(2):217-21. doi: 10.1161/01.hyp.34.2.217.
The localization of atherosclerotic lesions is influenced by hemodynamic factors, namely, shear stress and tensive forces. The present study investigated the relationships between shear stress and circumferential wall tension and between these hemodynamic factors and the intima-media thickness (IMT) of the common carotid artery in healthy men. Fifty-eight subjects were studied. Shear stress was calculated as blood viscosityxblood velocity/internal diameter. Circumferential wall tension was calculated as blood pressurexinternal radius. Blood velocity, internal diameter, and IMT were measured by high-resolution echo-Doppler. Mean shear stress was 12.6+/-3.3 dynes/cm(2) (mean+/-SD; range, 4.8 to 20.4) and was inversely related with age, blood pressure, and body mass index (BMI). Mean circumferential wall tension was 3.4+/-0.6x10(4) dynes/cm (range 2.4 to 5.6) and was directly associated with age and BMI. IMT was inversely associated with shear stress (r=0.55, P<0. 0001) and directly associated with circumferential wall tension (r=0. 43, P<0.0001). Shear stress and circumferential wall tension were inversely correlated (r=0.66, P<0.0001). In multiple regression analysis, shear stress and (marginally) cholesterol were independently associated with IMT, whereas circumferential wall tension, age, and BMI were not. These findings confirm that common carotid shear stress varies among healthy individuals and decreases as age, blood pressure, and BMI increase. Our findings also demonstrate that circumferential wall tension is directly associated with wall thickness, age, and BMI and that shear stress is associated with common carotid IMT independent of other hemodynamic, clinical, or biochemical factors.
动脉粥样硬化病变的定位受血流动力学因素影响，即剪切应力和张力。本研究调查了健康男性中剪切应力与周向壁张力之间的关系，以及这些血流动力学因素与颈总动脉内膜中层厚度（IMT）之间的关系。对58名受试者进行了研究。剪切应力计算为血液粘度×血流速度/内径。周向壁张力计算为血压×内半径。血流速度、内径和IMT通过高分辨率超声多普勒测量。平均剪切应力为12.6±3.3达因/平方厘米（平均值±标准差；范围为4.8至20.4），与年龄、血压和体重指数（BMI）呈负相关。平均周向壁张力为3.4±0.6×10⁴达因/厘米（范围为2.4至5.6），与年龄和BMI呈正相关。IMT与剪切应力呈负相关（r = 0.55，P < 0.0001），与周向壁张力呈正相关（r = 0.43，P < 0.0001）。剪切应力和周向壁张力呈负相关（r = 0.66，P < 0.0001）。在多元回归分析中，剪切应力和（勉强）胆固醇与IMT独立相关，而周向壁张力、年龄和BMI则不然。这些发现证实，健康个体的颈总动脉剪切应力各不相同，且随年龄、血压和BMI的增加而降低。我们的研究结果还表明，周向壁张力与管壁厚度、年龄和BMI直接相关，且剪切应力与颈总动脉IMT相关，独立于其他血流动力学、临床或生化因素。
