Di Bello V, Giampietro O, Matteucci E, Giorgi D, Bertini A, Piazza F, Talini E, Paterni M, Giusti C
Dipartimento di Medicina Interna, Università di Pisa.
G Ital Cardiol. 1998 Oct;28(10):1128-37.
Based on various epidemiological observations, it has been hypothesized that there is a "diabetic cardiomyopathy" strictly related to diabetes per se and probably due to an increase in the collagen content at the myocardial level, to microangiopathy or to complex alteration of myocardial metabolic pattern. Ultrasonic tissue characterization has recently been applied with different methodological approaches in order to identify early structural alterations of the myocardium.
We used two different methods of myocardial tissue characterization, i.e. integrated backscatter and videodensitometry, to analyze 26 type I diabetics without clinical symptoms, without hypertension or coronary artery disease, which were excluded on the basis of a negative exercise ECG, and in whom conventional echocardiographic parameters were normal. Seventeen healthy age- and sex-matched subjects were evaluated as the control group.
Of the common left ventricular functional indexes, only E/A ratio (expression of global diastolic function) was lower in diabetics compared with controls (p < 0.01). The integrated backscatter index (IBI%) at the septum and posterior wall was significantly higher in diabetics as compared to controls, expressing an increased collagen content on a myocardial level. The cyclic variation index (%) of the mean gray level (videodensitometry) was significantly lower in diabetics in comparison with controls, both for the septum (p < 0.0001) and posterior wall (p < 0.002). This probably expresses an altered intrinsic myocardial contractility, due to an increase in myocardial collagen content and/or impairment of micro-circulatory function.
In agreement with previous studies, we found an altered behavior in myocardial tissue reflectivity in type I diabetics. The real significance of this finding in the "normal" heart is the subject of intense debate. One hypothesis is that these findings could be considered a very early index of a "diabetic cardiomyopathy".
基于各种流行病学观察结果，有人提出假说，认为存在一种“糖尿病性心肌病”，它与糖尿病本身密切相关，可能是由于心肌层面胶原蛋白含量增加、微血管病变或心肌代谢模式的复杂改变所致。超声组织特征分析最近已通过不同的方法应用于识别心肌的早期结构改变。
我们使用两种不同的心肌组织特征分析方法，即背向散射积分和视频密度测定法，对26例无临床症状、无高血压或冠状动脉疾病的Ⅰ型糖尿病患者进行分析。这些患者基于运动心电图阴性被排除在外，且其传统超声心动图参数正常。17名年龄和性别匹配的健康受试者作为对照组进行评估。
在常见的左心室功能指标中，与对照组相比，糖尿病患者仅E/A比值（整体舒张功能的表达）较低（p < 0.01）。糖尿病患者室间隔和后壁的背向散射积分指数（IBI%）显著高于对照组，表明心肌层面胶原蛋白含量增加。糖尿病患者室间隔（p < 0.0001）和后壁（p < 0.002）的平均灰度（视频密度测定法）的周期性变化指数（%）显著低于对照组。这可能表明由于心肌胶原蛋白含量增加和/或微循环功能受损，心肌固有收缩性发生改变。
与先前的研究一致，我们发现Ⅰ型糖尿病患者心肌组织反射率存在改变。这一发现对于“正常”心脏的实际意义是激烈辩论的主题。一种假说认为，这些发现可被视为“糖尿病性心肌病”的一个非常早期的指标。
