Decreased Sample Entropy to Orthostatic Challenge in Anorexia NervosaJelinek HF1,2*, Cornforth DJ3, Tarvainen MP4,5, Spence I6 and Russell J7,8
- *Corresponding Author:
- Jelinek HF
Australian School of Advanced Medicine
Macquarie University, Sydney, Australia
E-mail: [email protected]
Received date: April 18, 2017; Accepted date: May 17, 2017; Published date: May 24, 2017
Citation: Jelinek HF, Cornforth DJ, Tarvainen MP, Spence I, Russell J (2017) Decreased Sample Entropy to Orthostatic Challenge in Anorexia Nervosa. J Metabolic Synd 6:226. doi:10.4172/ 2167-0943.1000226
Copyright: © 2017 Jelinek HF, et al. This is an open-access article distributed under the terms of the creative commons attribution license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Objective: The objective was to determine changes in heart rate variability (HRV) in response to orthostatic challenge in a convenience sample of patients with anorexia nervosa compared to age-matched controls. A decrease in HRV has been shown to correlate with an increased risk of heart attack in coronary artery disease and heart failure patients.
Method: Clinical data and ECG recordings were collected from 37 patients with eating disorders of which 16 had a diagnosis of anorexia nervosa and 42 controls. HRV was analyzed using linear and nonlinear methods during rest and orthostatic challenge from sitting to standing.
Results: Significant sympathovagal changes were identified in the anorexia nervosa group, especially with nonlinear HRV parameters and orthostatic challenge. Sample entropy, a nonlinear measure provided the best discrimination between the two groups on standing (1.58 ± 0.42 vs. 1.19 ± 0.4; p<0.0001) and when the change in HRV was measured from sitting to standing (-0.06 ± 0.36 vs. -0.42 ± 0.34; p<0.0001). The anorexia nervosa group had a significantly larger response to orthostatic challenge compared to the control group suggesting sympathetic dysfunction. Discussion: Including nonlinear measures and orthostatic challenge from an ECG recording of anorexia nervosa patients at initial clinical assessment on admission to hospital provides a noninvasive, sensitive tool to determine loss of normal physiological autonomic control of heart rate that may be related to an increased risk of arrhythmic events that requires further monitoring.
Conclusion: Nonlinear HRV measures are more sensitive in identifying sympathetic and parasympathetic changes associated with orthostatic challenge in patients with anorexia nervosa.