Epicardial fat thickness and nonalcoholic fatty liver disease in obese subjects

Abstract

Ectopic fat accumulation within the heart and the liver are linked to an increased cardiovascular risk. Ultrasound-measured cardiac and liver steatosis are easily accessible markers of intra-organ ectopic fat accumulation. The hypothesis that echocardiographic epicardial fat thickness is independently associated with nonalcoholic fatty liver disease (NAFLD) in obese subjects is tested. Sixty-two obese (BMI > 30 kg m⁻²) subjects with ultrasonographic evidence of NAFLD and 62 control obese subjects without history or signs of NAFLD underwent echocardiographic epicardial fat thickness measurement. Epicardial fat thickness was significantly higher (P < 0.01) in obese subjects with NAFLD when compared to those without NAFLD. Epicardial fat thickness was significantly higher (9.7 ± 0.2 vs. 8 ± 0.7 mm, P < 0.01) in subjects with severe (ultrasound score 3) than those with moderate (score 2) liver steatosis. Among waist circumference and BMI, epicardial fat thickness resulted in the best independent correlate of liver steatosis (R² = 0.77, P < 0.001). Our study suggests that epicardial fat is a good predictor of liver steatosis in obese subjects. Echocardiographic epicardial fat predicts ultrasound-measured fatty liver better than BMI or waist circumferences does. Patients with severe fatty liver infiltration presented with the highest amount of cardiac fat accumulation.