Threshold value of subepicardial adipose tissue to detect insulin resistance in obese children

Abstract

Until now, the association between subepicardial adipose tissue (SAT), insulin resistance and intima-media thickness (IMT) has not been evaluated in obese children. In this study, we evaluated whether echocardiographic SAT is related to insulin resistance and IMT in obese children. A total of 46 obese subjects (10.2+/-2.5 years of age, 25 male patients) and 30 age- and gender-matched lean subjects (10.8+/-3.1 years of age, 13 male patients) were included in this study. The criterion for diagnosing obesity was defined as the body mass index (BMI) being over 97% percentile of the same gender and age. Serum triglyceride (TG), low- and high-density lipoprotein, cholesterol, glucose and insulin levels were measured during the fasting state. Each subject underwent a transthoracic echocardiogram and the SAT thickness was measured during end-diastole from the parasternal long-axis views. The obese subjects had significantly higher SAT thickness and IMT values compared with the subjects in the control group (5.7+/-1.4 vs 3.0+/-0.7 mm, 0.78+/-0.15 vs 0.51+/-0.11 mm, P=0.001, respectively). Simple linear regression analysis showed no significant correlation between SAT and insulin resistance (r=0.170, P=0.253), whereas there was significant correlation between SAT and BMI, age and IMT (r=0.625, P=0.02, r=0.589, P=0.001, r=0.343, P=0.02, respectively). As an optimal cutoff point, a SAT thickness of 4.1 mm determined insulin resistance with 90% sensitivity and 61% specificity. Our study showed that SAT was significantly correlated with age, BMI and IMT, but not insulin resistance. However, our findings suggest that a 4.1 mm cutoff of SAT thickness might be used as a simple, inexpensive and non-invasive screening method because of its ability to predict insulin resistance with high sensitivity in obese children.