ULTRASOUND HISTOGRAM ANALYSES OF EPICARDIAL ADIPOSE TISSUE

Objective: Adipose tissue is a major endocrine organ and plays a key role in energy homeostasis. Two types of adipose tissue such as white and brown adipose tissue exist having essentially different physiological function. The epicardial adipose tissue (EAT) is considered as reliable marker of visceral adiposity, however its composition is not entirely clear. The aim of our study was to examine the qualitative features of EAT by ultrasound histograms in obese and normal-weight adolescents. Methods: 70 (mean age of 17.72 ? 1.20) randomly selected adolescents were involved in this study. Ultrasonographic histogram was used to assess the EAT structure by the contrast between the epicardial adipose tissue and left atrium (EAT/LA-value). Furthermore, anthropometric and biochemical parameters of cardiovascular risk were also obtained. Results: The EAT/LA-value differed significantly between normal weight and obese youngsters (14.76?0.83 vs. 26.22?0.95; p0.001) and was associated with clinical parameters of obesity (body mass index (BMI): r=0.57; p0.0001 and BMI percentile: r=0.72; p0.0001), laboratory parameters of cardiovascular risk factors (ALT: r=0.38; p<0.001, adiponectin: r= -0.33; p<0.01, hsCRP: r=0.24; p<0.05) and EAT thickness (EAT at end-systole: r=0.46; p<0.0001 and EAT at end-diastole: r=0.43; p<0.0001). Multiple regression analysis showed that the EAT/LA-value was associated with EAT at end-systole [B (95%CI) = 2.52 (0.94, 4.11); p≤0.01] and alanine aminotransferase (ALT) [9.23 (0.20, 18.26); p≤0.05 however, BMI proved to be the strongest independent predictor [0.16 (0.10, 0.21); p≤0.001 Conclusion: The ultrasound histogram of epicardial adipose tissue seems to be non-invasive, low-cost and easy imaging approach that can qualitatively distinguish between different types and characteristics of adipose tissue.