Estudo ecocadiográfico da função ventricular esquerda de pacientes com lipodistrofia generalizada congênita através da técnica de speckle tracking bidimensional

Abstract

Congenital generalized lipodystrophy (CGL) is an autosomal recessive disorder characterized by the absence of functional adipocytes and lipid stored in other tissues, including muscle and liver. Affected individuals develop severe insulin resistance, dyslipidemia, hepatic steatosis and diabetes, and usually with early cardiovascular mortality. Echocardiographic (ECHO) findings previously described in CGL used only the conventional technique and twodimensional speckle-tracking (ST2D), a new echocardiographic technique, allows the detection of early changes in myocardial function. Objective: Thus, this study aimed to use twodimensional speckle-tracking echocardiography (2D-STE) for the characterization and measurement of myocardial deformation in a sample of CGL patients. Design: A crosssectional study of 22 CGL patients and 22 healthy subjects, matched for sex and age, from 2013 to 2016. All participants undergone standard conventional ECHO and 2D-STE using Vivid 7 and Vivid 9 ultrasound system (GE Vingmed Ultrasound, Milwauke, Wi, USA). This technique includes global longitudinal strain (GLS) measure, obtained by evaluating the mean of the strain value of the 18 segments of the left ventricle (LV) in the three standard apical views. Biochemical evaluation was performed on the CGL group. Results: The mean age was 14.6 ± 10.7 years: 68.2% (15) participants < 18 years of age and 31.8% (7) participants 18 years of age. There were 59% (13) women. All CGL patients had hypoleptinemia, 95.4% (21) low HDLc, 86.4% (19) hypertriglyceridemia, 72.7% (16) severe insulin resistance, 68.2% (15) diabetes, 50% (11) hepatic steatosis, 41% (9) hyperinsulinemia, 41% (9) hypercholesterolemia and 18.2% (4) high blood pressure. When evaluated by conventional ECHO, all CGL group presented normal ejection fraction (EF), 36,6% (8) diastolic dysfunction, 31.8% (7) left ventricular hypertrophy (LVH), 27.3% (6) left atrial volume index (LAVI) increase, 18.2% (4) left ventricular systolic diameter (LVDS) increase and 4.5% (1) left ventricular diastolic diameter (LVDD) increase. Comparing CGL and control groups, the CGL subjects had higher LAVI and LV mass index (LVMI). Evaluation by 2D-STE showed abnormal results of global longitudinal strain (GLS) in 68.2% (15) of CGL group (p<0.01). The GLS was normal in all control group. CGL group also had abnormal results in the evaluation of GLS and in the all LV segments longitudinal strain (p<0.01), except for the apical segments. In the group of 22 patients with CGL, was found correlation between GLS and insulin (r=0.62, p=0.007), HbA1c (r=0.57, p=0.005), blood glucose (r=0.5, p=0.018) and HOMA-IR (r=0.5, p=0.021). A significant inverse correlation was noted between GLS and leptin (r = -0.51, p = 0.005). There was also correlation between age and SGL (r =0.45, p=0.03) in the same group. Conclusion: Two-dimensional speckle-tracking echocardiography revealed early left ventricular systolic dysfunction, even with a normal systolic function by conventional echocardiography in a young population with CGL. Early exposure to cardiovascular risk factors such as high blood glucose, HbA1c and HOMA-IR are related to myocardial damage.