Increased epicardial adipose tissue volume predicts insulin resistance and coronary artery disease in non-obese subjects without metabolic syndrome

Epicardial adipose tissue (EAT) reportedly secretes various adipokines that evoke insulin resistance in patients with obesity or metabolic syndrome. However, it remains unclear whether EAT also plays a role in the development of insulin resistance in lean subjects. The purpose of this study was to investigate the impact of EAT volume on the presence of insulin resistance and coronary artery disease in non-obese subjects without metabolic syndrome. We prospectively studied 624 consecutive patients who underwent multidetector computed tomography (MDCT) and measured EAT volume between January 2009 and June 2011. Obesity was defined as body mass index ≥ 25 kg/m2, and metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. After we excluded 385 patients with obesity or metabolic syndrome, 239 patients were enrolled in the present study. There were 102 (42.7%) subjects with insulin resistance (homeostasis model assessment ratio [HOMA-R] > 2.5) and 88 (36.8%) subjects with coronary artery disease. After adjusting for age, gender, and body mass index, increased EAT volume (≥ 35 ml mean EAT volume) was independently associated with insulin resistance (odds ratio 2.6, 95% confidence interval 1.5–4.8). Furthermore, increased EAT volume was also associated with coronary artery disease (odds ratio 1.9, 95% confidence interval 1.0–3.6) after adjustment of age, gender, body mass index, and the presence of insulin resistance. Increased EAT volume may play a key role in the development of insulin resistance and coronary artery disease, even in non-obese subjects without metabolic syndrome.