【作者】 张汝新；

【导师】 白小涓；

【作者基本信息】 中国医科大学 ， 内科学， 2004， 硕士

【摘要】 目的 心脑血管疾病是65岁以上老年人主要死亡原因之一，这些疾病的病理基础为动脉粥样硬化。年龄主要决定着动脉粥样硬化的进程。随着年龄的增加动脉会出现一系列增龄性变化，导致动脉壁的强度和弹性下降，从而促进动脉粥样硬化的发生和发展。彩色多普勒可对颈动脉管壁、血流动力学特征、狭窄程度、斑块形态等方面综合分析。本研究的对象尽可能地排除了动脉硬化危险因子的影响，目的为研究健康老年人颈动脉超声各参数的增龄性改变，探讨动脉粥样硬化的发生机制及血管的增龄性变化，为心脑血管疾病的诊治及预防提供相应的影像学依据。 方法 一、研究对象和分组 在沈阳市内汉口、新兴、鲲鹏、滑翔等八个社区对800名中老年人进行健康筛选。排除高血压、冠心病、糖尿病、脑血管病、高脂血症病史，不吸烟，测血压、血糖、血脂、肝功及肾功均正常，心电图、胸片元异常改变。符合上述条件共204名，男性105名，女性99名，年龄30-89岁。分为四个年龄组，30-44岁组52名；45-59岁组51名；60-74岁组50名；≥75岁组51名。 二、方法 所有受检者行颈动脉超声检查，使用美国HP SONOS 5500彩色多普勒超声显像仪，探头频率7.5HZ，轴分辨率为0.1 mm。B超检查读数均由医大一院超声室不了解临床诊断的同一名医师完成，被检查者取仰卧位，颈后薄枕，放松，头偏向检查区对侧，探头沿颈总动脉逐节段从前、侧、后三个方向观察其横轴及纵轴实时二维图像。 三、测量指标 1．颈总动脉(common carotid artery，CCA)内膜中层厚度(intima-media thickness，IMT)的测量：横纵向观察颈总动脉，颈总动脉后壁纵向超声显像可表现为由相对较低回声分割的两条平行亮线。内线为内膜与管腔的分界线，外线为中外膜分界线，其间距离即为IMT。锁定颈动脉窦以下Icm处(无斑块部位)质量好的图像，取左右两侧测量值的平均值为平均颈总动脉IMT。 2.斑块的测定:斑块定义为局限性回声结构突出管腔，IMT〕1 .3~。观察颈总动脉和颈动脉分叉处斑块情况，记录斑块数目，测量最大斑块厚度，半定量估计斑块的范围及严重程度:O级为无斑块;l级为单侧斑块毛Zmm;2级为单侧斑块>2~或双侧均有斑块且其中至少一侧斑块蕊2~;3级为双侧斑块均>2~。 3.颈总动脉内径(D):在两侧IMT最厚处测量前后壁内膜表面间的垂直距离，取均值。 4.双侧颈总动脉血流参数测定:收缩期峰值血流速度(peak systolicve-loeity;SPV);舒张期末血流速度(end diastolie veloeity;EDV);平均血流速度(TAV):收缩早期至舒张期末各点血流速度平均值;阻力指数(resistancein-dex;Rl):Rl=(SPV一EDV)/SPV;搏动指数(ptilsatility index;pl):pl=(SPV一EDV)/TAV 四、统计学处理 数据使用SPssll .5软件包进行分析。各项数据以均数土标准差表示，各年龄组数据间比较的显著性检验用方差分析，因素间相关性采用直线相关分析，并进行多元逐步回归分析，斑块发生率采用卡方检验，P<0.05为差异显著。结果 一、在CCA IMT、D、SPV、EDV、班、PI各项指标中不同年龄组之间组间差异明显，P<0.001，尤以〕60岁以上各组变化显著。 二、随着增龄，颈总动脉(CCA)内膜中层厚度(IMT)呈线性增加，斑块发生率随之增加，且斑块严重程度随IMT增加而增加。 三、随着增龄，颈总动脉内径(D)、阻力指数(RI)、搏动指数(PI)呈线性增加，收缩期峰值血流速度(SPV)及舒张期末血流速度(EDV)呈线性下降。 四、多因素分析年龄是影响健康人CCAIMT、D、sPv、EDv、RI、PI的独青田妄.J‘..‘司户习凡O结论 1.随着增龄，CCAIMT呈线性增加，斑块发生率随之增加，且斑块严重程度随IMT增加而增加，反映了IMT增厚是动脉粥样硬化的早期改变。 2.随着增龄，CCAD、RI、PI呈线性增加，SPV及EDV呈线性下降，年龄是影响健康老年人CCAIMT、D、SPV、EDV、Rl、PI的独立因素。 3.多参数评估有助于更好理解血管增龄。更多还原

【Abstract】 AimStudies indicate that cardio - cerebrovascular disease is a main reason which causes elder adults’death. The pathological basis of it is ahterosclerosis. Age has been found to be the chief determinant of atherosclerotic progression. A series changes occur with human aging in arteries, which causes the intensity and elasticity of the wall decreasing with age, which accelerate the atherosclerotic occurrence and development . Duplex ultrasound can generalize the alteration in carotid arterial structure function and hemodynamic parameters . The possible carrying risk factors of atherosclerosis are strictly excluded in present study. The purpose is to examine the relation of carotid ultrasonographic changes to the aging process, reveal the mechanism of atherosclerosis and provide preventive and diagnostic basis for clinical cardio - cerebrovascular disease.Method一 Subjects and GroupsSubjects who have hypertension coronary heart disease diabetes cardio -cerebrovascular disease and hyperlipoproteinemia are excluded. They are non-smokers with normal blood pressure plasma glucose concentration and plasma lipoprotein concentration, further evaluated by ECG . Aged from 30 to 89 years old,male 105 and femal 99. They are divided into four groups;30 -44years old 45 -59years old 60 -74years old,, and 75 years old.二 MethodCarotid ultrasound images are obtained in all subjects. Evaluation includes intima - media thickness (IMT) of common carotid artery (CCA) diastolic di-ameter(D) and serious degree and the numbers of plaque occurrence. Bloodflow parameters include peak systolic velocity ( SPV ) end diastolic velocity ( EDV) resistance index ( RI) and pulsatility index( PI).三 Statistical AnalysisSPSS11.5 statistical software is used for analysis. The arithmetic mean and standard deviation were used for descriptive statistics. Differences among groups are estimated using ANOVA procedure. To describe the dependency of the variables on age,we use liner regression analysis. A multiple stepwise regression a-nalysis is applied to CCAIMT D SPV EDV RI and PI as the dependent variable. Significance of differences in occurrence of plaques is calculated by x2 test. Probability value <0.05 is considered to indicate significance.Result一 Differences in index of CCAIMT D SPV EDV RI and PI among groups is significiant,P < 0.001,especially in groups of 60 years old.二 There is a liner correlation between IMT and age. The rate of plapue occurrence also increase with age, and IMT increase with the degree of plaque.三 CAD RI and PI increase significantly with age,but SPV and EDV have the reverse result.四 Stepwise regression analysis indicate that age is the only independent predictor in CCAIMT D SPV EDV RI and PI.Conclusion一. There is a liner increase in CCAIMT with age, the rate and degree of plaques increase with IMT thickening too, which reflects that IMT thickening is an early change in atherosclerosis.二. There is a liner increase in CCAD RI PI with age, SPV EDV have reverse results, the only independent factor to effect CCAIMT D SPV EDV RI and PI in healthy is age.三. A multiparametric assessment may contribute to a better understanding of vascular aging.更多还原