Abstract MP91: Abdominal Obesity, Independent of General Obesity, is Associated With Reduced Circadian Pattern of Cardiac Autonomic Modulation in Adolescents

Introduction: Reduced cardiac autonomic modulation (CAM) has been associated with metabolic syndrome and higher CVD risk in adults. However, the association between abdominal obesity and the circadian pattern of CAM has not been examined in adolescents. Hypothesis: We hypothesize that abdominal obesity is adversely associated with the circadian pattern of cardiac autonomic modulation in adolescents. Methods: We used data from the Penn State Child Cohort follow-up examination (N=421). Cardiac autonomic modulation was assessed by heart rate variability (HRV) analysis of 24-hour RR intervals, including frequency and time domain variables. We used 3-parameters from a cosine periodic regression to quantify the 24-hour HRV circadian pattern, namely, the mean levels of HRV indices (M), the amplitude of the oscillation (Â), and the timing of the highest oscillation (θ). A dual-energy x-ray absorptiometry was used to assess abdominal obesity, as android/gynoid fat ratio, visceral (VAT) and subcutaneous (SAT) fat a...