Spectral analysis of R-R interval variability by short-term recording in anorexia nervosa

Abstract

Subjects with anorexia nervosa (AN) present a number of changes in autonomic system functions, such as thermoregulation, vascular motility, heart rate and rhythm, and blood pressure. We evaluated the changes in the autonomic control of heart rate and blood pressure after postural variation by means of the spectral analysis of R-R interval variability (HRV in 13 female subjects with AN diagnosed on the basis of diagnostic statistical manual (DSM-IV) criteria, a mean age of 25 +/- 5.8 years and a mean body mass index (BMI) of 16.9 +/- 2.6. The controls were 16 healthy female subjects with a mean age of 25 +/- 2.3 years and a normal BMI. The data were statistically evaluated by means of one-way analysis of variance or Student's t test. The high frequency (HF) components of the spectral analysis did not significantly change when passing from clino- to orthostatism in the AN subjects, but there were significant changes in the controls. The changes in the low frequency (LF) components were similar in both groups, but smaller in the AN subjects. However, the difference between the two series was not statistically significant. The variance in the orthostatic R-R intervals recorded in the AN subjects was significantly less than the clinostatic intervals, the intervals recorded in the controls. These results indicate that AN subjects show signs of autonomic dysfunction. The increase in the HF component of the spectral analysis suggests that parasympathetic modulation is abnormally persistent during orthostatism, furthermore, the variability of the R-R intervals indicates that orthosympathetic regulation is also altered in AN.

A 6-weeks Treatment Program Improves HRV in Eating Disorder Patients

“…The present finding is consistent with previous results that eating disorder patients have symptoms of vagal hyperactivity [23][24][25][26]. This sympathovagal imbalance may contribute in part to cardiac autonomic dysfunction.…”

Decreased Sample Entropy to Orthostatic Challenge in Anorexia Nervosa

“…Studies on the changes in HRV following orthostatic challenge in AN patients have not produced consistent findings [27,2,36,28,32]. The time and frequency domain analysis in seated subjects showed no significant differences between the control and AN group in agreement with some previous studies [26,24,37].…”

“…However other studies report no difference in LF power [39]. Increased low frequency activity [21,23,28,32,6,40,7] and an unaltered HRV [41] or very similar HRV results with a decrease in LF have also been observed [42,27]. ECG recording and analysis from a sitting patient is not uncommon and has been shown not to influence HRV analysis significantly but may result in a lower parasympathetic amplitude response and higher sympathetic response [43,44].…”

“…Other studies report no change or altered sympathovagal balance [26,27]. Head-up tilt or HRV change following standing and investigating sympathetic and parasympathetic activity have also been reported [16,28] One study investigated influence of medication [29]. These highly controlled studies are essential in establishing physiological mechanisms and possible causes for disease development and progression but do not address the utility of HRV measures in a clinical situation at admittance to a treatment facility.…”

Pre-participation cardiac screening in young athletes: Models and criteria

“…Ishizawa et al (2008) reported that 32 AN patients had reduced sympathetic responsiveness and increased parasympathetic responsiveness compared with 37 healthy controls following a period of rest in the supine position. HRV appears to be abnormal in AN patients compared with healthy controls (Kriepe et al, 1994;Petretta et al, 1997;Casu et al, 2002;Melanson et al, 2004).…”