Purpose: 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.
Methods: 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.
Results: 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 (β = -1.182, P = 0.001).
Conclusions: 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.
1Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, JAPAN; 2Department of Radiation, Higashi Toride Hospital, Ibaraki, JAPAN; and 3Center for Tsukuba Advanced Research Alliance, University of Tsukuba, Ibaraki, JAPAN
Address for correspondence: Maeng-Kyu Kim, Ph.D., Department of Sports Medicine for Health and Disease, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan; E-mail: email@example.com.
Submitted for publication April 2009.
Accepted for publication June 2009.