Epicardial fat tissue: relationship with cardiorespiratory fitness in men

To explore the influence of the epicardial fat (EF) tissue on aspects of heart rate recovery (HRR) and cardiorespiratory fitness (V O2peak) in middle-aged men. A cross-sectional analysis of EF thickness was performed on 101 overweight or obese men. The men were categorized into low-EF, moderate-EF, and high-EF groups on the basis of ventricular EF thickness, as measured by transthoracic echocardiography. V O2peak was assessed with a graded maximal cycle ergometric test, including measurement of HRR 2 min after test cessation to estimate parasympathetic activity, with assessment of several metabolic parameters. Men in the highest and the middle EF thickness tertile had significantly slower recovery times than subjects in the lowest tertile, respectively (P < 0.05). Subjects with higher EF thickness were more likely to have impaired recovery and to reveal lower cardiorespiratory fitness than low-EF group subjects. There was a significant partial correlation, adjusted by age and body weight, between EF thickness and V O2peak (r = -0.25, P = 0.014). In the hierarchical multiple linear regression analyses, EF thickness was the strongest predicting variable associated with V O2peak in these population (beta = -1.182, P = 0.001). Higher EF thickness in men is associated with lower HRR at 1 and 2 min, a representation of autonomic dysfunction and poor cardiorespiratory fitness. These data suggest that moderately obese men with thicker EF tissue demonstrate reduced cardiorespiratory fitness and a differing parasympathetic response to exercise testing, as compared with men with lower EF levels.