Liver fat and visceral adiposity are involved in the development of the metabolic syndrome (MetS), and epicardial adipose tissue reflects visceral fat deposit which affects the cardiac autonomic system. The aim of this study was to determine if, and to what extent, epicardial fat thickness (EFT) and non-alcoholic fatty liver disease (NAFLD) are related to heart rate recovery (HRR) as a simple cardiac autonomic indicator in patients with MetS.Design and Method:
A total of 772 consecutive patients in health screening center who underwent abdominal ultrasonography, echocardiography and a treadmill test were enrolled. Echocardiographic EFT and HRR, defined as peak heart rate minus heart rate after a 1-minute recovery time, were measured. Patients were classified according to the presence of metabolic syndrome and NAFLD.Results:
EFT was significantly higher and HRR was significantly lower in NAFLD patients, especially in the MetS with NAFLD, compared to the non-MetS without NAFLD (MetS with NAFLD, EFT 7.5 ± 4.4 mm and HRR 31.9 ± 12.7; MetS without NAFLD, EFT 4.9 ± 3.0 mm and HRR 39.5 ± 11.1; non-MetS with NAFLD, EFT 5.9 ± 3.6 mm and HRR 36.6 ± 12.7; non-MetS without NAFLD, EFT 4.4 ± 3.5 mm and HRR 43.4 ± 14.5; p < 0.001). Patients with severe (n = 24, ultrasound score 3) showed significantly higher EFT than those with moderate liver steatosis (n = 123, score 2) (p's < 0.001), and EFT was positively correlated with the severity of liver steatosis (r = 0.431, p < 0.001). Moreover, HRR was significantly correlated with EFT (r = −0.386, p < 0.001) and the severity of liver steatosis (r = −0.324, p < 0.001).Conclusions:
EFT and NLFLD were significantly correlated with HRR in patients with MetS, and therefore may be best related to cardiovascular increased risk. Our result suggests a cross-link between epicardial fat, NLFLD and autonomic dysregulation in MetS.