ABC | Volume 114, Nº4, April 2020

Original Article Güneş et al. Epicardial adipose tissue and insulin resistance Arq Bras Cardiol. 2020; 114(4):675-682 Figure 1 – Receiver operator characteristic (ROC) curve of EAT to predict insulin resistance. Table 2 – Comparison of atrial electromechanical delay parameters measured by tissue Doppler imaging Obese patients with insulin resistance (n = 40) Obese patients without insulin resistance (n = 54) p Lateral PA, mean±SD, ms 62.2 ± 8.3 56.6 ± 8.4 0.002 Septal PA, mean ± SD, ms 46.1 ± 6.1 42.7 ± 5.9 0.019 Tricuspid PA, mean ± SD, ms 38.0± 5.8 36.1 ± 4.7 0.088 Inter-atrial EMD, median (IQR), ms 23 (18–30) 19.5 (15–23.5) 0.010 Intra-atrial EMD, median (IQR), ms 9.5 (6.2–10.0) 6 (4–9.2) 0.032 PA: Time interval from the onset of P-wave on surface ECG to the beginning of Am wave interval with tissue Doppler echocardiography; EMD: Electromechanical delay, IQR: Interquartile ranges. Table 3 – Echocardiographic parameters that correlate with HOMA-IR Variables Correlating with HOMA-IR R P Epicardial adipose tissue 0.422 < 0.001 Inter-atrial EMD 0.360 < 0.001 Intra-atrial EMD 0.345 0.001 Lateral PA 0.451 < 0.001 Septal PA 0.305 0.001 HOMA-IR: homeostatic model assessment for insulin resistance; PA: time interval from the onset of P-wave on surface ECG to the beginning of Am wave interval with tissue Doppler echocardiography; EMD: electromechanical delay. by inflammatory cytokines, such as IL-6, IL-1 and TFN-alpha secreted from this adipose tissue. Subclinical inflammation can both impair endothelial function and increase blood pressure by decreasing NO release. Another possible mechanism is: there may be sympathetic activation of both the obesity and the obesity-related inflammatory process. 36,44-47 Our study had some limitations: its main limitation was the relatively small sample size. Echocardiographic EAT is a linear measurement. Thus, it may not assess the total epicardial fat volume that varies at several myocardial locations. As a result of EAT, metabolically active tissue, inflammatory cytokines and inflammatory markers could be investigated in future studies. The absence of waist circumference measurement was another limitation, precluding the determination of a relationship between waist circumference and epicardial fat. Conclusion In conclusion, epicardial adipose tissue is a cheap, easily accessible parameter that can be easily measured with echocardiography and used to identify insulin resistance among children. Since atrial electromechanical delay increased in obese children with insulin resistance, it should be followed closely for atrial fibrillation. 679