An association between eating disorder behaviors and autonomic dysfunction in a nonclinical population. A pilot study

Heart Rate Variability Reactivity to Food Image Stimuli is Associated with Body Mass Index

Appetitive control is driven by the hedonic response to food and affected by several factors. Heart rate variability (HRV) signals have been used to index autonomic activity and arousal levels towards visual stimuli. The current research aimed to examine the influence of body mass index (BMI), disordered eating behaviors, and sex on the HRV reactivity to food in a nonclinical sample. Thirty-eight healthy male and sixty-one healthy female participants completed questionnaires assessing disordered eating symptoms. HRV was recorded when the participants received visual stimuli of high-calorie food, neutral and negative emotional signals. Generalized estimating equation models were used to investigate the associations between HRV, BMI, disordered eating behaviors, and sex across the three stimulus types. Male participants demonstrated a higher ratio of low-frequency power to high-frequency power (LF/HF) than females across all the stimulus types. An increase in LF/HF reactivity to food signals was observed in all the study subjects. The moderation effect of BMI on LF/HF in response to food signals was also observed. Our study suggests that body weight may play a role in the interaction between sympathetic activity and food stimuli; however, how the interaction between sympathetic activity and food stimuli contributes to diet control warrants further investigation.

Assessing for Eating Disorders: A Primer for Gastroenterologists

Eating disorders involve irregularities in eating behavior that may cause gastrointestinal (GI) symptoms. Consequently, many patients with eating disorders seek gastroenterological healthcare at some point in their illness, with many seeking this care even before they seek treatment for and/or diagnosed with their eating disorder. As such, the gastroenterology provider is in a unique position to identify, manage, and facilitate treatment for an eating disorder early in the course of the illness. Although assessing eating disorders is already a difficult task, the identification of eating disorders in patients with GI disease represents an even greater challenge. In particular, common GI symptoms, such as nausea, vomiting, and bloating, may disguise an eating disorder because these symptoms are often viewed as a sufficient impetus for dietary restriction and subsequent weight loss. In addition, the focus on identifying an organic etiology for the GI symptoms can distract providers from considering an eating disorder. During this prolonged diagnostic evaluation, the eating disorder can progress in severity and become more difficult to treat. Unfortunately, a misconception that hinders eating disorder detection is the notion that the rate or method of weight loss is associated with an eating disorder. Regardless of whether weight loss is slow or rapid, purposeful or accidental, eating disorder behaviors and thought patterns may be present. Unidentified eating disorders are not only dangerous in their own right but also can interfere with effective management of GI disease and its symptoms. As such, it is imperative for the GI provider to remain well versed in the identification of these diseases.

Cardiac biomarkers of disordered eating as a function of diagnostic subtypes

OBJECTIVE

The purpose of this study was to identify cardiac biomarkers of disordered eating as a function of diagnostic subtype as assessed via self-report inventory.

METHOD

Mean heart rate (HR), systolic and diastolic blood pressure, mean R wave amplitude (mV), mean T wave amplitude (mV), QTc interval (sec), Tpeak-Tend interval prolongation (sec), QTc interval prolongation (sec), QRS prolongation (sec), and spectral indicators of cardiac dysfunction (LF/HF spectral ratio, HF spectral power) were assessed via electrocardiography among women with no eating disorder symptoms (n = 32), subclinical eating disorder symptoms (n = 92), anorexia nervosa (n = 7), bulimia nervosa (n = 89), binge eating disorder (BED: n = 20), and other specified feeding and eating disorders (OSFED: n = 19).

RESULTS

MANOVA results showed statistically significant group differences. Follow-up tests revealed significantly decreased mean R wave amplitude among participants with self-indicated clinical (bulimia nervosa, binge eating disorder) and subclinical forms of disordered eating compared to asymptomatic controls.

DISCUSSION

Results suggest decreased mean R wave amplitude is a promising cardiac biomarker of disordered eating.

Resting state heart rate variability in clinical and subthreshold disordered eating: A meta-analysis

OBJECTIVE

Research has demonstrated mixed results regarding the direction of the association between vagal activation and disordered eating. The current meta-analysis examined studies testing the link between resting-state heart rate variability indices of vagal activation (vmHRV), and both clinical and subthreshold disordered eating.

METHOD

A systematic search of the literature resulted in the inclusion of studies that were correlational (associations between HRV and disordered eating symptoms) and that examined group differences (e.g., control group vs. disordered eating group), for a total of 36 samples.

RESULTS

Findings indicated a small but reliable association of vmHRV with disordered eating, r = 0.12, indicating greater vagal activation in individuals with disordered eating compared to those with little or no disordered eating behavior. Moderation analyses identified predictors of the vmHRV/disordered eating association. Bulimia nervosa was found to have a large, positive effect size with vmHRV, r = 0.60, which was significantly greater than all other types of disordered eating, Q _T = 10.74, p = .047. Compared to subthreshold disordered eating, clinical eating disorders demonstrated significant, persistent increased vagal activation with a medium, reliable effect size, r = 25, Q_T = 3.94, p = .045.

CONCLUSION

These insights contribute to an improved understanding of the pathophysiology in disordered eating.

Sexes on the brain: Sex as multiple biological variables in the neuronal control of feeding

Neuronal interactions at the level of vagal, homeostatic, and hedonic circuitry work to regulate the neuronal control of feeding. This integrative system appears to vary across sex and gender in the animal and human worlds. Most feeding research investigating these variations across sex and gender focus on how the organizational and activational mechanisms of hormones contribute to these differences. However, in limited studies spanning both the central and peripheral nervous systems, sex differences in feeding have been shown to manifest not just at the level of the hormonal, but also at the chromosomal, epigenetic, cellular, and even circuitry levels to alter food intake. In this review, we provide a brief orientation to the current understanding of how these neuronal systems interact before dissecting selected studies from the recent literature to exemplify how feeding physiology at all levels can be affected by the various components of sex.

Maintenance of parasympathetic inhibition following emotional induction in patients with restrictive type anorexia nervosa

This study aimed to explore changes in heart rate variability (HRV), a proxy for parasympathetic activity characterizing emotion regulation processes before, during and after negative emotional induction in patients suffering from restrictive type anorexia nervosa (AN-RT). We compared two methods of HRV analysis, the Fast Fourier Transform high frequency (FFT-HF) and a specific HRV high frequency analysis technique, namely, the wavelet transform HRV (WT-HRV). A sample of 16 inpatients with AN-RT was compared to 24 control participants. Heart rate (HR) was continuously recorded for 5 min before the beginning of the video until 5 min after the video. The participants answered questionnaires concerning their eating behaviors, mood disorders and difficulties in emotion regulation. During the entire procedure, the FFT-HF in patients was lower than that in controls. Using the WT-HRV, the patients did not differ from the controls at baseline, and only the controls showed a decrease during emotional induction. After the video, the WT-HRV in patients began to decrease during the first 2 min of emotional recovery although the WT-HRV in controls was already increased. These results highlighted the disturbances in the physiological dynamics of emotion regulation processes in patients with AN-RT.

Postprandial cardiac autonomic function in Prader-Willi syndrome

CONTEXT

Individuals with Prader-Willi syndrome (PWS) have a high cardiovascular risk, the mechanism of which is unclear. There may be dysfunction in the autonomic nervous system (ANS) in PWS.

OBJECTIVE

To measure, as indicators of cardiac autonomic function, postprandial heart rate variability (HRV) and arterial stiffness in adults with PWS.

METHODS

Ten adults with PWS were compared with 11 matched healthy obese subjects and 9 healthy lean subjects. Electrocardiographic traces and arterial stiffness were recorded over a period of 10 minutes at -60, 0, 30, 60, 120 and 240 minutes after consumption of a standardized 600-kCal breakfast. Frequency domain analysis was performed using fast Fourier transform to estimate power spectral density in the full spectrum and in low-frequency (LF 0·04-0·15 Hz) and high-frequency (HF 0·15-0·40 Hz) bands.

RESULTS

ANCOVA revealed a reduced LF HRV meal response in adults with PWS compared with obese controls, with no differences in HF HRV, LF/HF ratio, heart rate, total power or arterial stiffness meal responses.

CONCLUSIONS

This study assessed cardiac autonomic function in adults with PWS compared with matched obese and lean subjects in response to a meal. Results suggest impaired postprandial ANS responsiveness in PWS, which could contribute to both the known increased cardiovascular risk and obesity.

Diurnal patterns of salivary cortisol and DHEA in adolescent anorexia nervosa

Although there is well-documented evidence for hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis function in anorexia nervosa (AN), there has been little research into secretory patterns of salivary cortisol and dehydroepiandrosterone (DHEA) in this condition. The cortisol awakening response (CAR), a prominent and discrete feature of the cortisol cycle, has not been extensively explored in adolescent AN. Saliva samples were collected at awakening, 30 min and 12 h post-awakening on two consecutive weekdays from eight female adolescents with clinically diagnosed AN and 41 healthy control (HC) age-matched females. Adolescent AN patients had greater salivary cortisol and DHEA concentrations than HC girls at all points. Increased hormone secretion was unrelated to body mass index. However, despite hypersecretion of both hormones, the circadian pattern including the CAR paralleled that of the HC group. Findings from this preliminary study confirm dysregulation of HPA axis function in adolescent AN as evidenced by hypersecretion of both cortisol and DHEA, which share the common secretagogue adrenocorticotropic hormone. However, the parallel diurnal profiles for AN and HC participants, including the CAR, may indicate hypersecretion per se rather than differential regulation of the diurnal pattern of these two adrenal steroids in AN.