Conte Lorenzo, Fabiani Iacopo, Barletta Valentina, Bianchi Cristina, Maria Ciccarone Anna, Cucco Cuono, De Filippi Marianna, Miccoli Roberto, Prato Stefano Del, Palombo Carlo, Di Bello Vitantonio
Departement of Surgical, Medical, Molecular and Critical Area Pathology, Pisa, Italy.
Departement of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
J Cardiovasc Echogr. 2013 Jul-Sep;23(3):73-80. doi: 10.4103/2211-4122.123953.
Diabetes mellitus (DM) represents by itself a major risk factor for cardiovascular events and the coexistence of obesity with consequent left ventricular volumetric overload could be responsible for further damages on left ventricular function. Aim of this study was to demonstrate the effect of body mass index (BMI) on left ventricular function in diabetes patients with no cardiovascular complications and with normal ejection fraction (EF).
We evaluated 71 stable asymptomatic diabetes patients in optimal medical treatment and 24 healthy controls (C) (45% females; mean age: 58.4 +/- 9.4 years; BMI: 23.5 +/- 1.5). We stratified diabetes patients into two groups according to BMI: BMI <30 kg/m (A: 44 patients; 47% females; mean age: 60.9 +/- 6.6 years; BMI: 25.7 +/- 1.9; Diabetes duration: 9.1 +/- 9.5 years); BMI >30 kg/m (B: 27 patients; 37% females; mean age: 56.2 +/- 7.8 years; BMI: 33.0 +/- 2.1; Diabetes duration: 8.5 +/- 5.2 years). The following parameters were evaluated by conventional two dimensional (2D) echocardiography (GE VIVID 7) and tissue Doppler imaging (TDI): left ventricular dimensions (LVIDd; PWTd; IVSd), Left Ventricular Volumes (EDV, ESV), EF (by biplane Simpson's method), Left Ventricular Mass (by ASE formula), peak mitral annular velocity at septal and lateral levels (Sm and Sl). Global longitudinal strain (GLS) was obtained off line by Speckle tracking imaging method using Echopac 10 software.
Groups A, B were comparable for diabetes duration and glycated hemoglobin level, history of hypertension, and lipid profile. The EF was similar in the three groups, (A: 64 +/- 6%; B: 63 +/- 4%; C: 61 +/-5%; = NS). LVMass indexed for height was significantly higher in A and B in comparison with C (A: 45.2 +/- 8.1 g/m; B: 46.1 +/- 9.6 g/m; C: 39.5 +/- 4.9 g/m; < 0.05). The stroke volume index (SVi) was significantly lower in B vs A (B: 35.3 +/- 5.7 ml/m; A: 39.3 +/7.1 ml/m; = 0.033). GLS was significantly lower in group B respect A and C (C: 20.9 +/- 1.3%; A: -20.3+/-2.6%; B: -19 +/- 2; < 0.05; < 0.01).
In uncomplicated asymptomatic DM patients, the presence of first degree obesity plays an incremental role in adversely affecting left ventricular function and remodeling. The conventional echocardiographic methods such as the EF and the TDI are not so sensitive to identify the early LV dysfunction such as the evaluation of GLS by Speckle Tracking echocardiography. The longitudinal subendocardial fibers dysfunction in diabetes/obese patients could be derived by the complex interaction between metabolic (diabetes) and hemodynamic/endocrine abnormalities.
糖尿病本身就是心血管事件的主要危险因素，肥胖的并存以及随之而来的左心室容量超负荷可能会对左心室功能造成进一步损害。本研究的目的是证明体重指数（BMI）对无心血管并发症且射血分数（EF）正常的糖尿病患者左心室功能的影响。
我们评估了71例接受最佳药物治疗的稳定无症状糖尿病患者和24例健康对照者（C组）（45%为女性；平均年龄：58.4±9.4岁；BMI：23.5±1.5）。我们根据BMI将糖尿病患者分为两组：BMI<30kg/m²（A组：44例患者；47%为女性；平均年龄：60.9±6.6岁；BMI：25.7±1.9；糖尿病病程：9.1±9.5年）；BMI>30kg/m²（B组：27例患者；37%为女性；平均年龄：56.2±7.8岁；BMI：33.0±2.1；糖尿病病程：8.5±5.2年）。通过传统二维（2D）超声心动图（GE VIVID 7）和组织多普勒成像（TDI）评估以下参数：左心室尺寸（LVIDd；PWTd；IVSd）、左心室容积（EDV、ESV）、EF（采用双平面辛普森法）、左心室质量（采用ASE公式）、室间隔和侧壁水平的二尖瓣环峰值速度（Sm和Sl）。使用Echopac 10软件通过斑点追踪成像方法离线获得整体纵向应变（GLS）。
A组和B组在糖尿病病程、糖化血红蛋白水平、高血压病史和血脂谱方面具有可比性。三组的EF相似（A组：64±6%；B组：63±4%；C组：61±5%；P=无显著性差异）。与C组相比，A组和B组的身高指数化左心室质量显著更高（A组：45.2±8.1g/m²；B组：46.1±9.6g/m²；C组：39.5±4.9g/m²；P<0.05）。与A组相比，B组的每搏输出量指数（SVi）显著更低（B组：35.3±5.7ml/m²；A组：39.3±7.1ml/m²；P=0.033）。与A组和C组相比，B组的GLS显著更低（C组：20.9±1.3%；A组：-20.3±2.6%；B组：-19±2；P<0.05；P<0.01）。
在无并发症的无症状糖尿病患者中，一度肥胖的存在对左心室功能和重塑产生不利影响。传统超声心动图方法如EF和TDI对识别早期左心室功能障碍不如斑点追踪超声心动图评估GLS敏感。糖尿病/肥胖患者的心内膜下纵向纤维功能障碍可能源于代谢（糖尿病）与血流动力学/内分泌异常之间的复杂相互作用。
