Heart rate variability and left ventricular diastolic function in anorexia nervosa

A new conceptual model for anorexia nervosa: A role for connective tissue?

The etiology of anorexia nervosa (AN) remains to be fully elucidated, and current theories also fail to account for the direct effect of starvation on the health of the organs and tissues, specifically the connective tissue present in most organs of the body. Individuals with hereditary disorders of connective tissue manifest with clinical symptoms that overlap with AN, as the abnormal connective tissue also contributes to many of the other extra-articular manifestations of these hereditary disorders. This article hypothesizes that a similar pathophysiology may also contribute to the clinical presentation of AN. Therefore, a better understanding is needed to elucidate: (1) the relationship between abnormal connective tissue and AN, (2) the impact of starvation toward the development of abnormal connective tissue and how this manifests clinically, (3) the etiology of autonomic nervous system changes contributing to the dysautonomia in AN, and (4) how the sensory signals sent from potentially abnormal connective tissue to the central nervous system impact interoception in AN. A conceptual model incorporating abnormal connective tissue is provided. PUBLIC SIGNIFICANCE: The etiology of AN remains poorly understood and current theories fail to account for the direct impact of starvation on the health of the organs and tissues of the body. There is significant clinical overlap between AN and hereditary connective tissue disorders. This paper attempts to provide a new conceptual model for AN in which abnormal connective tissue contributes to the underlying pathogenesis.

Evaluation of measurement accuracy of wearable devices for heart rate variability

This paper proposed a method based on heart rate variability (HRV) for evaluating the accuracy of wearable devices in measuring heart rate. HRV refers to the variation in time intervals between successive heartbeats, widely used in many fields such as clinical and sports fields. Wearable devices such as Electrocardiogram (ECG) electrode patches have gained popularity due to their portability and ease of use. However, they can be prone to measurement interference caused by environmental noise, human respiration, etc. The proposed method consists of four main components: selection of "gold standard measurement devices", identification of HRV measurement metrics, construction of an HRV evaluation framework, and quantification of measurement errors. The method is validated through simulated experiments using ECG patches. The evaluation framework and quantification model established in this method have significant implications in establishment of industry standards and diagnosis of diseases in clinical practice.

Emergency room presentations of people with anorexia nervosa

People with anorexia nervosa (AN) tend to shy away from engaging in typical primary care provider relationships in order to avoid detection. Therefore, they may seek care for their medical concerns through a local emergency department (ED). Inherently, AN is associated with a litany of medical complications, which become more prevalent as the severity of their eating disorder increases. Notwithstanding the typical young age at the onset of AN, no body system is immune to these medical complications. Thus, ED providers may need to pursue a medical diagnosis in order to explain presenting symptoms in people with AN. In addition to the medical issues, AN is also a serious mental illness with high mortality rates, including deaths by suicide. Therefore, ED providers also need to be familiar with relevant mental health issues for these people.

Assessment and management of cardiovascular complications in eating disorders

BACKGROUND

Eating disorders (EDs) are serious conditions predominantly affecting adolescents and young adults (AYAs) and pose a considerable threat to their health and wellbeing. Much of this increased morbidity and mortality is linked to medical compromise, especially cardiovascular abnormalities. Rates of presentation to both community and inpatient medical settings have increased in all age groups following the Covid-19 pandemic and subsequent "lockdowns", with patients presentations being more medically compromised compared to previous years. This has implications for clinicians with regard to the performance of competent cardiovascular assessments and management of findings.

AIMS

This paper is a practical resource for clinicians working with AYAs in whom EDs may present. It will provide a brief summary of the physiological context in which cardiovascular complications develop, systematically outline these complications and suggest a pragmatic approach to their clinical evaluation.

METHODS

Relevant literature, guidelines and academic texts were critically reviewed. Conclusions were extracted and verified by a Child and Adolescent Psychiatrist and Adolescent Paediatrician, with suitable expertise in this clinical cohort.

CONCLUSIONS

The cardiovascular complications in EDs are primarily linked to malnutrition, and patients presenting with Anorexia Nervosa are most often at greatest risk of structural and functional cardiac abnormalities, including aberrations of heart rate and rhythm, haemodynamic changes and peripheral vascular abnormalities. Other cardiovascular abnormalities are secondary to electrolyte imbalances, as seen in patients with Bulimia Nervosa. More recently defined EDs including Avoidant/Restrictive Food Intake Disorder and Binge Eating Disorder are also likely associated with distinct cardiovascular complications though further research is required to clarify their nature and severity. Most cardiovascular abnormalities are fully reversible with nutritional restoration, and normalisation of eating behaviours, including the cessation of purging, though rare cases are linked to cardiac deaths. A detailed clinical enquiry accompanied by a thorough physical examination is imperative to ensure the medical safety of AYAs with EDs, and should be supported by an electrocardiogram and laboratory investigations. Consideration of cardiovascular issues, along with effective collaboration with acute medical teams allows community clinicians identify those at highest risk and minimise adverse outcomes in this cohort.

Emotional and autonomic response to visual erotic stimulation in patients with functional hypothalamic amenorrhea

Introduction

Functional hypothalamic amenorrhea (FHA) is a clinical condition associated with high levels of physiological and psychological stress ranging from weight loss to maladaptive behavior and coping skills. A reliable measure of the psychophysiological response to stress and the ability to cope with stimuli is heart rate variability (HRV). Through the sympathetic (SNS) and parasympathetic nervous system (PNS), the autonomic nervous system (ANS) promotes various changes in HRV that reflect the individual's psychophysiological response to stress. FHA patients are characterized by high levels of PNS activation during psychological load, suggesting that parasympathetic hyperactivation could be a pathology marker.

Methods

In the present study, we examine changes in HRV during observation of erotic, neutral, and disgusting images in 10 patients with FHA [(mean ± S.D.) age: 26.8 ± 5.9] and in 9 controls (age: 25.4 ± 6.4; BMI: 22.47 ± 2.97) to assess the differential activation of PNS and SNS between FHA patients and controls matched for age and without other clinical conditions.

Results

Our results showed that FHA patients had significantly higher HRV activation while observing high emotional value images and not during the observation of neutral images confirming a parasympathetic hyperactivation.

Discussion

HRV and cognitive and psychological testing, could provide new insights into understanding such a clinically understudied condition and provide further tools for clinical diagnosis and treatment.

Interoceptive Awareness and Anorexia Nervosa: When Emotions Influence the Perception of Physiological Sensations

ABSTRACT

Anorexia nervosa (AN) is related to difficulties in emotion regulation, including a deficit in interoceptive awareness. The lack of interoceptive awareness is considered a vulnerability involved in the development and maintenance of anorexic symptoms. Surprisingly, no study has been conducted that focuses on these associations in an emotional context. This study measures the interoceptive awareness-using heartbeat self-counting and a sphygmomanometer-of 25 subjects suffering from AN and 25 control subjects, first at rest and then in an emotional situation. The results show that a deficit in interoceptive awareness was observed for the subjects suffering from AN at rest as well as when an emotional context was induced. This study encourages future investigations to focus on the impact of interoceptive deficit in AN to develop as efficient a care regimen as possible for these subjects.

Cardiac Remodeling and Its Determinants in Anorexia Nervosa Adolescents: Impact of Weight Recovery

Cardiovascular alterations in anorexia nervosa (AN) adolescents include bradycardia and decreased systolic blood pressure and left ventricular mass. However, their determinants remain poorly understood. We assessed the associations between morphological and functional left ventricular (LV) remodeling, autonomic control by heart rate variability (HRV) analysis, thyroid hormones and brain natriuretic peptide (BNP) levels in AN female adolescents without or with weight recovery (WR). Fifty-nine female adolescents including 16 AN patients without WR (mean age 13.9 years (10−16)), 10 AN patients with WR (15.7 years (12−18)) and 33 controls (14.1 years (10−18)) underwent night heart rate (HR) recording to measure HRV (and especially SD1/SD2, the ratio between instantaneous (SD1) and long-term (SD2) standard deviation of R-R intervals, reflecting sympatho-vagal balance), speckle tracking echocardiography to assess LV global longitudinal strain (GLS) and blood test for dosage of tri-iodothyronine (T3) hormone and NT-proBNP. Compared to controls, AN patients without WR presented with lower HR (55 ± 7 vs. 68 ± 6 bpm; p < 0.001), parasympathetic hyperactivity, and higher GLS (−19.2 ± 1.8 vs. −16.9 ± 2.8%; p = 0.009). These alterations were partly abolished in AN patients with WR. In a multivariate regression analysis, T3 was the main factor explaining the variance of SD1/SD2, a sympatho-vagal balance marker. NT-proBNP levels were not correlated with cardiac alterations. AN patients had parasympathetic hyperactivity linked with their rate of T3, and a higher GLS. These alterations were partly restored in AN patients with WR.

Long-term cardiac assessment in a sample of adolescent-onset anorexia nervosa

BACKGROUND

High mortality rates have been reported in patients with anorexia nervosa, mainly due to cardiovascular alterations. The purpose of the present study was to assess cardiac structural and functional abnormalities some 20 years after initial treatment in a sample of adolescent-onset anorexia nervosa (A-AN) and to compare them with matched healthy controls (HC).

METHODS

A sample of 29 women diagnosed and treated for AN during adolescence (A-AN) were assessed more than 20 years later. A complete cardiac evaluation was carried out including an electrocardiogram (ECG) and a standard 2D echocardiography. Thirty matched HC were also assessed.

RESULTS

In the A-AN group, four subjects had a body mass index lower than 18.5 and met full DSM 5 criteria for AN at follow-up (Low-Weight group). They were compared with the rest of the sample (n = 25) who had normalized their weight (Normal-Weight group), though some still showed some eating disorder symptoms. Both groups were compared with the HC group. Subjects in the Low-Weight group presented statistically significant decreases in the left ventricular end-diastolic and left atrium dimensions and left ventricular mass in comparison with the Normal-Weight group and the HC. No other differences in cardiac parameters were found between groups.

CONCLUSIONS

Echocardiographic and ECG parameters of adults who had presented A-AN twenty years earlier and currently maintained normal weight were similar to those of HC who had never been treated or diagnosed with AN. Adult subjects with A-AN who still had low weight in the long term present certain cardiac abnormalities similar to those seen in short-lasting disease. More studies are needed to confirm these results in a larger sample.

Determinants of severe bradycardia in adolescents hospitalized for anorexia nervosa

BACKGROUND

Severe bradycardia is an indication supporting hospitalization in adolescents with eating disorders. Some adolescents with anorexia nervosa (AN) and significant weight loss present with a normal pulse rate at admission, whereas others have severe bradycardia, suggesting that total weight loss is not the most important determinant of bradycardia. The aims of this study were to define the prevalence of severe bradycardia as the cause for hospital admission in adolescents with AN, to evaluate correlations between known determinants of severe bradycardia and pulse rate at admission, and to evaluate the average time required to recover from severe bradycardia after re-feeding.

METHODS

Ninety-nine hospitalized patients with AN were enrolled. Weight loss history, anthropometric, laboratory, and electrocardiogram data were collected at admission to and at discharge from hospital. Multivariate analysis was performed to detect the most important determinants of severe bradycardia.

RESULTS

Forty-eight percent of the AN patient admissions were due to severe bradycardia (AN-B+ group). Patients in this group had a higher maximum lifetime weight (P = 0.0045), greater premorbid weight loss (P = 0.0011), and more rapid weight loss (P = 0.0001). Multivariate analysis showed that recent weight loss is an independent predictor of bradycardia at hospital admission (R² : 0.35, P = 0.0001). Severe bradycardia normalized after minimal weight gain of 0.25 ± 0.18 kg/day for 3-10 days.

CONCLUSIONS

This study confirms that recent weight loss is probably the most important determinant of severe bradycardia in adolescents with AN.

Cardiac abnormalities identified with echocardiography in anorexia nervosa: systematic review and meta-analysis

BACKGROUND

Anorexia nervosa affects most organ systems, with 80% suffering from cardiovascular complications.

AIMS

To define echocardiographic abnormalities in anorexia nervosa through systematic review and meta-analysis.

METHOD

Two reviewers independently assessed eligibility of publications from Medline, EMBASE and Cochrane Database of Systematic Reviews registries. Studies were included if anorexia nervosa was the primary eating disorder and the main clinical association in described cardiac abnormalities. Data was extracted in duplicate and quality-assessed with a modified Newcastle-Ottawa scale. For continuous outcomes we calculated mean and standardised mean difference (SMD), and corresponding 95% confidence interval. For dichotomous outcomes we calculated proportion and corresponding 95% confidence interval. For qualitative data we summarised the studies.

RESULTS

We identified 23 eligible studies totalling 960 patients, with a mean age of 17 years and mean body mass index of 15.2 kg/m2. Fourteen studies (469 participants) reported data suitable for meta-analysis. Cardiac abnormalities seen in anorexia nervosa compared with healthy controls were reduced left ventricular mass (SMD 1.82, 95% CI 1.32-2.31, P < 0.001), reduced cardiac output (SMD 1.92, 95% CI 1.38-2.45, P < 0.001), increased E/A ratio (SMD -1.10, 95% CI -1.67 to -0.54, P < 0.001), and increased incidence of pericardial effusions (25% of patients, P < 0.01, 95% CI 17-34%, I2 = 80%). Trends toward improvement were seen with weight restoration.

CONCLUSIONS

Patients with anorexia nervosa have structural and functional cardiac changes, identifiable with echocardiography. Further work should determine whether echocardiography can help stratify severity and guide safe patient location, management and effectiveness of nutritional rehabilitation.

Pathophysiological mechanisms of bradycardia in patients with anorexia nervosa

BACKGROUND

The purpose of this investigation was to examine heart rate variability (HRV), interbeat interval (IBI), and their interrelationship in healthy controls, bradycardic hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4) mutation carriers, and patients with anorexia nervosa (AN). We tested the hypothesis that neural mechanisms cause bradycardia in patients with AN. Therefore, we assumed that saturation of the HRV/IBI relationship as a consequence of sustained parasympathetic control of the sinus node is exclusively detectable in patients with AN.

METHODS

Patients with AN between the ages of 12 and 16 years admitted to our hospital due to malnutrition were grouped and included in the present investigation (N = 20). A matched-pair group with healthy children and adolescents was created. Groups were matched for age and sex. A 24-hour Holter electrocardiography (ECG) was performed in controls and patients. More specifically, all patients underwent two 24-hour Holter ECG examinations (admission; refeeding treatment). Additionally, the IBI was recorded during the night in HCN4 mutation carriers (N = 4). HRV parameters were analyzed in 5-minute sequences during the night and plotted against mean corresponding IBI length. HRV, IBI, and their interrelationship were examined using Spearman's rank correlation analyses, Mann-Whitney U tests, and Wilcoxon signed-rank tests.

RESULTS

The relationship between IBI and HRV showed signs of saturation in patients with AN. Furthermore, signs of HRV saturation were present in two HCN4 mutation carriers. In contrast, signs of HRV saturation were not present in controls.

CONCLUSIONS

The existence of HRV saturation does not support the existence of parasympathetically mediated bradycardia. Nonneural mechanisms, such as HCN4 downregulation, may be responsible for bradycardia and HRV saturation in patients with AN.

Autonomic Nervous System Function in Anorexia Nervosa: A Systematic Review

Background: Autonomic nervous system (ANS) dysfunction has been suggested to contribute to the high prevalence of cardiovascular complications in individuals with anorexia nervosa (AN), yet has not been thoroughly investigated. The current review aimed to synthesize the evidence of basal ANS function in individuals with a current diagnosis of AN and those with a previous diagnosis who had achieved weight restoration, as compared to controls.

Methods: A systematic review of nine databases was conducted and studies that were published in a peer-review journal, in English, that included at least one assessment of ANS function in individuals with a current or previous diagnosis of AN were selected. Forty-six studies were included with a total of 811 participants with a current diagnosis of AN and 123 participants with a previous diagnosis of AN.

Results: ANS function was assessed through heart rate variability (n = 27), orthostatic challenge, blood pressure variability or baroreflex sensitivity (n = 11), adrenergic activity (n = 14), skin conductance level (n = 4), and pupillometry (n = 1). Individuals with AN demonstrated increased parasympathetic activity and decreased sympathetic activity, suggestive of autonomic dysregulation. Following weight restoration, autonomic function trended toward, or was equivalent to, control levels.

Discussion: Autonomic dysregulation is indicated through a range of assessments in individuals with AN. Future investigations should utilize a variety of assessments together in order to conclusively establish the nature of autonomic dysfunction in AN, and following extended weight restoration. Moreover, investigation into the co-occurrence of ANS function and cardiovascular risk is required.

Heart rate variability as a biobehavioral marker of diverse psychopathologies: A review and argument for an "ideal range"

Heart rate variability (HRV), a measure of the variability in intervals between subsequent heart beats, is now widely considered an index of emotion regulatory capacity and the ability to adapt flexibly to changing environmental demands. Abnormalities in HRV are implicated in a host of psychopathologies, making it a potentially powerful transdiagnostic biobehavioral change mechanism in treatment interventions. While most mental illnesses are associated with low HRV, eating disorders have been linked to elevated HRV. We examined 62 research articles on HRV in psychopathology to test the hypothesis that there is an "ideal range" of HRV that predicts optimal functioning. Relationships between symptom severity and parameters that quantify HRV were examined graphically. More extreme time-domain HRV measures, both high and low, were associated with psychopathology, whereas healthy controls displayed mid-range values. Findings preliminarily support the hypothesis that there is an "ideal range" of HRV that could be targeted in biofeedback interventions.

Heart rate variability as a biomarker for anorexia nervosa: A review

OBJECTIVE

Anorexia nervosa (AN) typically begins in early adolescence and other than weight status has few reliable biomarkers. Early diagnosis is a critical prognostic factor, but this can be clinically challenging. Heart rate variability (HRV), the beat-by-beat variance in heart rate (HR), may provide a unique assessment for the presence of AN because it has clinical utility as a biomarker of cardiac autonomic control in various populations (e.g., athletes, the aged, those with cardiovascular diseases, etc.). We present a review of the literature examining HRV in those with AN.

METHOD

Relevant publications were selected from PubMed using the search terms 'anorexia nervosa AND (HR OR HRV)'. Twenty papers were selected and reviewed.

RESULTS

The majority of studies suggest that those with AN have markedly and consistently elevated HRV compared to controls, even greater than among young athletes. However, no studies have explored HRV as a biomarker for AN.

DISCUSSION

Future studies on HRV should elucidate its role as a diagnostic biomarker for AN as well as its responsiveness with serial measurement to track response rates and predict relapse.

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.

Heart and anorexia nervosa

Anorexia nervosa, one of the more frequent and severe eating disorders, is a chronic psychiatric disease with potentially serious somatic consequences. This behavioral symptomatology leads to weight loss, undernutrition, and more or less severe-potentially life-threatening-somatic complications including respiratory, hepatic, digestive and cardiac features, electrolyte disturbances, endocrine and bone impairment, immunodepression, and related opportunistic infections. In this review, the authors report an overview of cardiac diseases in this disease.

Moving beyond self-report data collection in the natural environment: A review of the past and future directions for ambulatory assessment in eating disorders

OBJECTIVE

In recent years, ecological momentary assessment (EMA) has been used to repeatedly assess eating disorder (ED) symptoms in naturalistic settings, which has allowed for increased understanding of temporal processes that potentiate ED behaviors. However, there remain notable limitations of self-report EMA, and with the rapid proliferation of technology there are ever-increasing possibilities to improve ambulatory assessment methods to further the understanding and treatment of EDs. Therefore, the purpose of this review was to (a) systematically review the studies in EDs that have utilized ambulatory assessment methods other than self-report, and (b) provide directions for future research and clinical applications.

METHOD

A systematic literature search of electronic databases was conducted, and data regarding study characteristics and methodological quality were extracted.

RESULTS

The search identified 17 studies that used ambulatory assessment methods to gather objective data, and focused primarily on autonomic functioning, physical activity, and cognitive processes in ED and control groups.

DISCUSSION

Together the literature demonstrates the promise of using a range of ecologically valid ambulatory assessment approaches in EDs, though there remains limited research that has utilized methods other than self-report (e.g., wearable sensors), particularly in recent years. Going forward, there are several technology-enhanced momentary assessment methods that have potential to improve the understanding and treatment of EDs.

Medical Complications of Eating Disorders in Youth

Eating disorders affect a significant number of individuals across the life span and are found among all demographic groups (including all genders, socioeconomic statuses, and ethnicities). They can cause malnutrition, which can have significant effects on every organ system in the body. Cardiovascular complications are particularly dangerous and cause eating disorders to have the highest mortality rate of all mental illnesses. This article outlines the medical assessment and treatment of malnutrition due to disordered eating.

Autonomic Nervous System Response during Light Physical Activity in Adolescents with Anorexia Nervosa Measured by Wearable Devices

Anorexia nervosa (AN) is associated with a wide range of disturbances of the autonomic nervous system. The aim of the present study was to monitor the heart rate (HR) and the heart rate variability (HRV) during light physical activity in a group of adolescent girls with AN and in age-matched controls using a wearable, minimally obtrusive device. For the study, we enrolled a sample of 23 adolescents with AN and 17 controls. After performing a 12-lead electrocardiogram and echocardiography, we used a wearable device to record a one-lead electrocardiogram for 5 min at baseline for 5 min during light physical exercise (Task) and for 5 min during recovery. From the recording, we extracted HR and HRV indices. Among subjects with AN, the HR increased at task and decreased at recovery, whereas among controls it did not change between the test phases. HRV features showed a different trend between the two groups, with an increased low-to-high frequency ratio (LF/HF) in the AN group due to increased LF and decreased HF, differently from controls that, otherwise, slightly increased their standard deviation of NN intervals (SDNN) and the root mean square of successive differences (RMSSD). The response in the AN group during the task as compared to that of healthy adolescents suggests a possible sympathetic activation or parasympathetic withdrawal, differently from controls. This result could be related to the low energy availability associated to the excessive loss of fat and lean mass in subjects with AN, that could drive to autonomic imbalance even during light physical activity.

Respiratory sinus arrhythmia reactivity across empirically based structural dimensions of psychopathology: A meta-analysis

Low resting respiratory sinus arrhythmia (RSA) is observed in many mental health conditions, including anxiety disorders, mood disorders, schizophrenia spectrum disorders, disruptive behavior disorders, and nonsuicidal self-injury, among others. Findings for RSA reactivity are more mixed. We evaluate associations between RSA reactivity and empirically derived structural categories of psychopathology-including internalizing, externalizing, and thought problems-among physically healthy adults. We searched multiple electronic databases for studies of RSA among participants who were assessed either dimensionally using well-validated measures or diagnostically using structured interviews. Strict inclusion criteria were used to screen 3,605 published reports, which yielded 37 studies including 2,347 participants and 76 effect sizes. We performed a meta-analysis, with meta-analytic regressions of potential moderators, including psychopathology subtypes. The sample-wide meta-analytic association between RSA reactivity and psychopathology was quite small, but heterogeneity was considerable. Moderation analyses revealed significant RSA reactivity (withdrawal) specifically in externalizing samples. Additional moderators included (a) stimulus conditions used to elicit RSA reactivity (only negative emotion inductions were effective), (b) sex (women showed greater RSA reactivity than men), and (c) adherence to established methodological guidelines (e.g., higher electrocardiographic sampling rates yielded greater RSA reactivity). These findings indicate that associations between RSA reactivity and psychopathology are complex and suggest that future studies should include more standardized RSA assessments to increase external validity and decrease measurement error.

Echocardiographic Assessment of Ventricular Function During Exercise in Adolescent Female Patients With Anorexia Nervosa

BACKGROUND

Patients with anorexia nervosa (AN) have altered physiologic responses to exercise. The aim of this study was to investigate exercise capacity and ventricular function during exercise in adolescent patients with AN.

METHODS

Sixty-six adolescent female patients with AN and 21 adolescent female control subjects who exercised to volitional fatigue on a semisupine ergometer, using an incremental step protocol of 20 W every 3 min, were retrospectively studied. Heart rate, blood pressure, and echocardiographic Doppler indices were measured at rest and during each stage of exercise. Fractional shortening, rate-corrected mean velocity of circumferential fiber shortening, stress at peak systole, cardiac output, and cardiac index were calculated. Minute ventilation, oxygen consumption, carbon dioxide production, and respiratory exchange ratio were measured using open-circuit spirometry.

RESULTS

Patients with AN had significantly lower body mass index (16.7 vs 19.7 kg/m², P < .001), total work (1,126 vs 1,914 J/kg, P < .001), and test duration (13.8 vs 20.8 min, P < .001) compared with control subjects. Peak minute ventilation, oxygen consumption, and carbon dioxide production were significantly decreased in patients with AN. Heart rate, systolic blood pressure, cardiac index, fractional shortening, and rate-corrected mean velocity of circumferential fiber shortening demonstrated similar patterns of increase with progressive exercise between groups but were decreased at peak exercise in patients with AN. Body mass index percentile, age, peak oxygen consumption, and peak cardiac output were independently associated with exercise duration.

CONCLUSIONS

Adolescent patients with AN have reduced exercise capacity and peak cardiovascular indices compared with control subjects but normal patterns of cardiovascular response during progressive exercise. Systolic ventricular function is maintained during exercise in adolescents with AN.

Blood Pressure, Heart Rate Variability, and Adiposity in Caribbean Pre-pubertal Children

Childhood obesity prevalence has increased over the last 30 years. The Heart Rate Variability (HRV) studies performed in adults suggest a possible relation between abnormal autonomic regulation and hypertension in the situation of overweight or obesity. Objective: The aims of this study were to explore the early relationships between adiposity and blood pressure and HRV in pre-pubertal children. Methods: Data were collected during the medical examination of the follow-up at 7 years of the TIMOUN mother-child cohort in Guadeloupe. Body Mass Index z-score (zBMI), sum of tricipital and subscapular skinfold thickness, percentage of fat mass, and Waist-to-Height Ratio were measured. A global corpulence score was computed using a Principal Component Analysis (PCA). Systolic Blood Pressure (SBP) and HRV parameters (cardiac holter monitoring) were collected under 2 conditions (calm and tachycardial period). Relations between HRV, SBP, each adiposity indicator and the corpulence score were studied with restricted cubic splines models, and linear regression models. The age at adiposity rebound (AR) was estimated from the individual growth curves. Results: 575 children were included in the SBP study (mean age: 7.7 years, from 85 to 99 months). SBP was linearly correlated with the corpulence score and the zBMI. An increase of 1 in the zBMI was associated with an increase of 2.3 (±0.28) mmHg in SBP. The effect-size of zBMI on SBP was higher in children with early age at AR. Compared to children with normal BMI, children with a zBMI <™2SD had their RMSSD, SDNN, LF and HF indicators in tachycardial conditions significantly reduced by -30, -21, -37, and -48%, respectively. In boys with a zBMI >2SD, we observed a global increase in all HRV parameters (under tachycardial conditions), particularly the LF [β = 0.43 (±0.18)]. Conclusion: In pre-pubertal period a positive correlation between adiposity excess and SBP was observed with significant changes of HRV in boys, arguing for an early abnormal autonomic regulation and for early preventive intervention in the infancy period, particularly in case of overweight or obesity. Thinness was associated with a reduction in almost all the HRV parameters studied, when compared to normal corpulence, suggesting a decrease in autonomic influence.

Predictors of Complications in Anorexia Nervosa and Atypical Anorexia Nervosa: Degree of Underweight or Extent and Recency of Weight Loss?

PURPOSE

Adolescents with atypical anorexia nervosa (AAN) can experience severe physical complications despite not being underweight, posing questions about the contribution of weight loss to complications experienced in restrictive eating disorders (EDs). This study compared total weight loss and recent weight loss with admission weight as predictors of physical and psychological complications.

METHODS

Retrospective (2005-2010) and prospective (2011-2013) studies were undertaken of 12- to 19-year-old hospitalized adolescents with anorexia nervosa (AN) or AAN, defined as meeting criteria for AN except underweight (≥85% median body mass index). Predictors were total weight loss (from lifetime maximum), recent weight loss (past 3 months), and admission weight. Outcomes were hypophosphatemia, clinical, anthropometric, and psychometric markers during admission.

RESULTS

In 171 participants (AN, 118 [69%]; AAN, 53 [31%]), there was little evidence of an association between weight measures and hypophosphatemia. Greater total weight loss (regression coefficient [Coeff]: -1.70, 95% confidence interval [CI]: -2.77, -.63, p = .002) and greater recent weight loss (Coeff: -3.37, 95% CI: -5.77, -.97, p = .006), but not admission weight, were associated with a lower pulse rate nadir. Greater total weight loss (odds ratio [OR]: 1.70, 95% CI: 1.19, 2.24, p = .003) and greater recent weight loss (OR: 2.12, 95% CI: 1.11, 4.02, p = .02) were also associated with a higher incidence of bradycardia.

CONCLUSIONS

In adolescents with restrictive EDs, total weight loss and recent weight loss were better predictors than admission weight of many physical complications. This suggests that future diagnostic criteria for AN place greater emphasis on weight loss.

Hypothesis: Clues From Mammalian Hibernation for Treating Patients With Anorexia Nervosa

This hypothesis is that anorexia nervosa (AN) is a biologically driven disorder, and mammalian hibernation may offer clues to its pathogenesis. Using this approach, this hypothesis offers suggestions for employing heart rate variability as an early diagnostic test for AN; employing the ketogenic diet for refeeding patients, attending to omega 3:6 ratio of polyunsaturated fatty acids (PUFAs) in the refeeding diet; and exploring clinical trials of the endocannabinoid-like agent, palmitoylethanolamde for patients with AN. This hypothesis also explores the role of lipids and autoimmune phenomena in AN, and suggest a lipodomics study to search for antibodies in the serum on patients with AN.

Security Hunger-Strike Prisoners in the Emergency Department: Physiological and Laboratory Findings

BACKGROUND

Medical treatment of hunger-strike patients, especially those in incarceration facilities, may pose clinical and treatment challenges for the treating physicians.

OBJECTIVE

The aim of our study is to describe the epidemiology and clinical and laboratory characteristics of hunger-strike prisoners presenting to the emergency department (ED) and to describe etiologies of hospitalization and complications among this group.

METHOD

We retrospectively examined clinical and laboratory manifestations of 50 hunger-strike prisoners who were referred for evaluation to the ED after a longstanding fast.

RESULTS

After a mean of 38 (28-44) days of a hunger strike, the most common complaints were chest pain and abdominal pain (14/60 [23.3%], 13/60 [21.6%], respectively). Mean weight loss percentage was 18.5%, and most patients were bradycardic (25/40 [62.5%]), and some hypothermic (16/50, [32%]). We describe several laboratory disturbances observed in these patients; leukopenia was the most common hematologic manifestation (31/50 [62%]), and a prolonged international normalized ratio was observed in 12/29 (41.3%) patients. We hospitalized 12% of the patients; the most common hospitalization cause was bradycardia (3/6 [50%]).

CONCLUSIONS

Our study found that the most common clinical symptom was chest pain, which has not been previously reported among hunger strikers. We observed a substantial number of laboratory disturbances due to muscle wasting and protein loss and due to presumed vitamin and micronutrient deficiencies. We suggest monitoring electrocardiograms for heart rate, blood count, chemistry, coagulation tests, and vitamin levels.

Characterization and correlates of exercise among adolescents with anorexia nervosa and bulimia nervosa

OBJECTIVE

To characterize exercise behaviors among adolescents with anorexia nervosa (AN), atypical AN, or bulimia nervosa (BN), and determine associations between exercise and medical risk.

STUDY DESIGN

Cross-sectional electronic medical records of all patients evaluated by the Eating Disorder Program at Stanford between January 1997 and February 2011 were retrospectively reviewed.

RESULTS

1,083 subjects (961 females, 122 males; mean age 15.6) met eligibility criteria. Most patients (89.7%) reported exercise (mean 7.0 h per week over mean 5.4 days per week) prior to presentation. Running (49.9%), calisthenics (40.7%), walking (23.4%), soccer (20.9%), and swimming (18.2%) were the most common exercises; a majority (60.6%) reported team sport participation. Males were less likely to report team exercise (p = .005). Bradycardia (heart rate <50) at presentation was associated with team sport participation (adjusted odds ratio [AOR] 1.66, 95% confidence interval [CI] 1.02-2.72) and hours of exercise per week (AOR 1.05, 95% CI 1.02-1.09), controlling for diagnosis, sex, age, duration of illness, rate of weight loss, and percent median body mass index (%mBMI).

DISCUSSION

Adolescents with AN, atypical AN, and BN reported high levels of exercise. Females reported more team sport participation. Greater exercise frequency and team sport participation were associated with bradycardia. Further studies assessing the relationship between exercise and bradycardia may help inform the medical management of adolescents with these eating disorders who are more physically active.

Medical complications of anorexia nervosa

Anorexia nervosa is a psychiatric disorder with potential life-threatening medical sequelae. This article reviews the principal medical complications associated with anorexia nervosa, highlights associated diagnostic pitfalls and emphasizes the importance of a multidisciplinary approach to management.

Cardiovascular Impact of Eating Disorders in Adults: A Single Center Experience and Literature Review

Eating disorders have multiple medical sequelae, including potentially life-threatening cardiovascular complications. This article describes our cardiology practice experience of treating adults with eating disorders in the outpatient setting and documents baseline cardiac findings in this complex patient population. We describe our findings in patients across the spectrum of eating disorders; past studies have generally focused on anorexia only. This article also includes a review of the current literature on cardiovascular complications associated with disordered eating.

Cardiac changes in anorexia nervosa

Introduction Anorexia nervosa is an eating disorder, which is associated with many different medical complications as a result of the weight loss and malnutrition that characterise this illness. It has the highest mortality rate of any psychiatric disorder. A large portion of deaths are attributable to the cardiac abnormalities that ensue as a result of the malnutrition associated with anorexia nervosa. In this review, the cardiac complications of anorexia nervosa will be discussed.

METHODS

A comprehensive literature review on cardiac changes in anorexia nervosa was carried out.

RESULTS

There are structural, functional, and rhythm-type changes that occur in patients with anorexia nervosa. These become progressively significant as ongoing weight loss occurs.

CONCLUSION

Cardiac changes are inherent to anorexia nervosa and they become more life-threatening and serious as the anorexia nervosa becomes increasingly severe. Weight restoration and attention to these cardiac changes are crucial for a successful treatment outcome.

Medical complications of anorexia nervosa and their treatments: an update on some critical aspects

Anorexia nervosa has the highest mortality rate of any psychiatric disorder. Many of the deaths are attributable to medical complications which arise as the malnutrition and weight loss worsens. Every body system may be adversely affected by anorexia nervosa. Yet, remarkably, most of the medical complications of anorexia nervosa are treatable and reversible with optimal medical care, as part of a multidisciplinary team who are often involved in the care of these patients. Herein, we will describe the medical complications of anorexia nervosa and their treatments.

Relationship between duration of illness and cardiac autonomic nervous activity in anorexia nervosa

Background

The mortality rate associated with anorexia nervosa (AN) is high, and death is mainly attributable to cardiac events. A wide range of autonomic nervous system disturbances may be mechanisms underlying the increased cardiovascular mortality and sudden death of patients with AN. Heart rate variability (HRV) has been proven to be a reliable noninvasive method for quantitative assessment of sympathetic and parasympathetic regulation of heart rate (HR). The longer the duration of illness of AN patients, the higher the mortality rate. However, there have been few reports on the relationship between the duration of illness and HRV in AN. Hence, the aims of this study were to compare the cardiac autonomic nervous activity (CANA) of female patients with AN and age-matched female controls and to evaluate the relationship between the duration of illness and the CANA of the AN patients.

Methods

We studied 14 female patients with AN and 22 age-matched healthy women. Beat-to-beat heart rate variability, recorded in a supine position, was investigated using power spectral analysis.

Result

Mean heart rate was positively correlated with normalized high-frequency (HF: 0.15 to 0.40 Hz) power and negatively correlated with the low-frequency (LF: 0.04 to 0.15 Hz)/HF power (LF/HF) ratio of the controls. On the other hand, duration of illness was negatively correlated with normalized HF power and positively correlated with the LF/HF ratio of the AN patients.

Conclusions

These results suggest that, given that the LF/HF ratio is an estimate of cardiac sympathovagal balance, anorectic patients with a long illness duration display lower vagal tone (parasympathetic withdrawal) and high sympathetic tone.

The role of wearable sensors and wireless technologies for the assessment of heart rate variability in anorexia nervosa

PURPOSE

Bradycardia and abnormal cardiac autonomic function are related to increased mortality in anorexia nervosa (AN). The aim of this study was to assess heart rate (HR) and HR variability of young adolescents with AN as compared to controls by means of wearable sensors and wireless technologies.

METHOD

The ECG signal was recorded in 27 AN girls and 15 healthy girls at rest using a wearable chest strap. The tachogram, the mean intervals between R peaks (meanRR), the root mean square of successive differences (RMSSD), the power of low-frequency (LF) and high-frequency (HF) bands and the LF/HF ratio were assessed.

RESULTS

All AN girls showed a reduced HR and an increased meanRR and RMSSD. An HF increase, a LF decrease, and a LF/HF reduction indicated a prevalence of the parasympathetic on sympathetic activity.

CONCLUSIONS

The instruments used in this pilot study were feasible, unobtrusive and extremely suitable in AN subjects who are burdened by high incidence of cardiovascular mortality; their application could open to new approaches of vital signs monitoring in hospitals as well as in home settings.

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.

Cardiovascular disorders in anorexia nervosa and potential therapeutic targets

Anorexia nervosa (AN) is an eating disorder in which a distorted self-perception of body image and an excessive fear of gaining weight result in extreme restrictions in eating habits. AN may be divided into two types: a "binge-eating/purging type" during which the individual regularly engages in overeating and then purging behavior, and a "restricting type", in which she does not. AN is a serious medical problem in young people in Western societies. It is widely reported that patients with AN exhibit an enhanced mortality rate as compared with age-matched healthy subjects, which has been mainly ascribed to cardiac complications. At least one-third of all deaths in patients with anorexia nervosa are estimated to be due to cardiac causes, mainly sudden death. Cardiovascular complications of AN can be present in up to 80% of cases, and among them alterations in cardiac electrical activity, structure and hemodynamics have been reported as causes of morbidity and mortality. The objective of this brief review is to summarize current knowledge on the main cardiovascular complications of AN, their underlying mechanisms and the possible therapeutic approaches.

Eating disorders in children and adolescents: state of the art review

Despite their high prevalence, associated morbidity and mortality, and available treatment options, eating disorders (EDs) continue to be underdiagnosed by pediatric professionals. Many adolescents go untreated, do not recover, or reach only partial recovery. Higher rates of EDs are seen now in younger children, boys, and minority groups; EDs are increasingly recognized in patients with previous histories of obesity. Medical complications are common in both full and subthreshold EDs and affect every organ system. No single cause of EDs has emerged, although neurobiological and genetic predispositions are emerging as important. Recent treatment paradigms acknowledge that they are not caused by families or chosen by patients. EDs present differently in pediatric populations, and providers should have a high index of suspicion using new Diagnostic and Statistical Manual, 5th edition diagnostic criteria because early intervention can affect prognosis. Outpatient family-based treatment focused on weight restoration, reducing blame, and empowering caregivers has emerged as particularly effective; cognitive behavioral therapy, individual therapy, and higher levels of care may also be appropriate. Pharmacotherapy is useful in specific contexts. Full weight restoration is critical, often involves high-calorie diets, and must allow for continued growth and development; weight maintenance is typically inappropriate in pediatric populations. Physical, nutritional, behavioral, and psychological health are all metrics of a full recovery, and pediatric EDs have a good prognosis with appropriate care. ED prevention efforts should work toward aligning with families and understanding the impact of antiobesity efforts. Primary care providers can be key players in treatment success.

Heart rate variability in adolescents with functional hypothalamic amenorrhea and anorexia nervosa

Aim of this study consisted in assessing the 24-h heart rate variability (HRV), a measure of autonomic nervous system (ANS) imbalance, in 21 adolescents with functional hypothalamic amenorrhea (FHA, 11 normogonadotropic, N-FHA, and 10 hypogonadotropic, Hy-FHA) compared to 21 patients with anorexia nervosa (AN) and 21 controls. As expected, subjects with AN showed a significant dysregulation in multiple HRV parameters, while Hy-FHA patients presented with a dysregulation in a few domains (SDNN, HFr), which was not present in girls with N-FHA, who showed values largely similar to controls. FHA might represent part of the AN biological spectrum, and a link between these two conditions might exist, possibly related to the degree of psychological and/or hormonal dysfunction.

The significance of bradycardia in anorexia nervosa

Anorexia nervosa (AN) is a life-threatening condition, with a significant risk for death, due to cardiovascular complications. It is characterized by abnormal eating behavior and has the highest mortality rate of all psychiatric disorders. It has been associated with bradycardia (a heart rate [HR] of less than 60 beats per minute) (up to 95%), hypotension, mitral valve prolapse, and heart failure. The diagnosis of AN can be elusive, and more than half of all cases are undetected. The purpose of this study was to raise and improve awareness to the possible diagnosis of AN in adolescent and young adult patients with weight loss displaying bradycardia and new cardiac disorders. Clinical characteristics, HR, and electrocardiographic data of 23 consecutive patients (20 females) with AN and of 10 young adults (8 females) without AN, between the years 2006 and 2009, were recorded and summarized. At presentation 16/23 (69.6%) showed HR < 50 bpm. The mean lowest HR of all patients was 44 ± 6 (range 26 to 68) bpm. No patient needed pacemaker therapy. Bradycardia in young adults, especially females with weight loss, should raise the possible diagnosis of AN, so it can be treated early in-time, and thus prevent premature death.

Pilot study employing heart rate variability biofeedback training to decrease anxiety in patients with eating disorders

Heart rate variability (HRV) biofeedback, a technique which encourages slow meditative breathing, was offered to 25 in-patients with various eating disorder diagnoses-anorexia nervosa, bulimia nervosa and binge eating disorder. We found that this modality had no serious side effects, and was subjectively useful to most participants. An enhanced ability to generate highly coherent HRV patterns in patients with recent onset anorexia nervosa was observed.

ED management of patients with eating disorders

BACKGROUND

Eating disorders are one of the "great masqueraders" of the twenty-first century. Seemingly healthy young men and women with underlying eating disorders present to emergency departments with a myriad of complaints that are not unique to patients with eating disorders. The challenge for the Emergency Medicine physician is in recognizing that these complaints result from an eating disorder and then understanding the unique pathophysiologic changes inherent to these disorders that should shape management in the emergency department.

OBJECTIVE

In this article, we will review, from the perspective of the Emergency Medicine physician, how to recognize patients with anorexia and bulimia nervosa, the medical complications and psychiatric comorbidities, and their appropriate management.

CONCLUSIONS

Anorexia and bulimia nervosa are complex psychiatric disorders with significant medical complications. Recognizing patients with eating disorders in the ED is difficult, but failure to recognize these disorders, or failure to manage their symptoms with an understanding of their unique underlying pathophysiology and psychopathology, can be detrimental to the patient. Screening tools, such as the SCOFF questionnaire, are available for use by the EM physician. Once identified, the medical complications described in this article can help the EM physician tailor management of the patient to their underlying pathophysiology and effectuate a successful therapeutic intervention.

Convalescent resting tachycardia predicts unfavorable outcome of anorexia nervosa

BACKGROUND

In patients with anorexia nervosa (AN) who have tachycardia during the clinical course, difficulty in treatment has been observed. The purpose of the present study was to evaluate the association between heart rate (HR) in the weight loss and weight recovery periods, and outcome.

METHODS

The subjects consisted of 40 girls with AN (age at onset, 8-16 years). The outcome 1-5 years after the initiation of treatment was regarded as favorable for both bodyweight within 15% of the standard weight and regular menstruation during the last 6 months, and unfavorable for bodyweight <85% of the standard weight and absent or nearly always absent menstruation. HR during the weight loss period was obtained at the outpatient clinic on the first visit. For HR during the weight recovery period, we used the resting and peak HR obtained in exercise tolerance test, which was performed when the bodyweight successfully increased along with improvement in physical complications. The association between each HR and outcome was evaluated.

RESULTS

Favorable outcomes were observed in 19 of the 40 patients after the 1 year follow up but in 32 after the 5 year follow up. Resting HR during the weight recovery period was higher throughout the 5 years in the unfavorable than in the favorable outcome group, with significant differences after the 2, 4, and 5 year follow ups.

CONCLUSION

In AN, resting tachycardia during the convalescent period is associated with unfavorable outcome.

Exercise electrocardiography extinguishes persistent junctional rhythm in a patient with severe anorexia nervosa

Among psychiatric conditions, anorexia nervosa carries the highest mortality, in part due to the propensity for rhythm disturbances among patients with advanced disease. Patients with anorexia nervosa are prone to both bradycardia and tachyarrhythmias, though mortality has not been associated with the former. To date, only one case of junctional rhythm in the setting of anorexia nervosa has been previously described, which was unremitting and required prolonged hospitalization. We report a case of persistent accelerated junctional rhythm where a formal exercise electrocardiography study demonstrated rapid reversion to sinus rhythm with graded exercise. Despite a 22-day hospitalization the patient never reverted permanently to sinus rhythm. This underscores the heightened vagal tone that may be seen among patients with severe anorexia nervosa. Despite this, it may be rapidly extinguished with sympathetic overdrive during exercise. In this context, exercise electrocardiography appears to be a safe, noninvasive means of assessing cardiac conduction and chronotropic reserve in this population.

Echocardiographic findings in adolescents with anorexia nervosa at beginning of treatment and after weight recovery

Anorexia nervosa (AN) is an eating disorder with somatic complications. The aim of the study was to analyse echocardiographic abnormalities in patients with AN at initial examination and after weight restoration. A total of 173 consecutively admitted adolescents (aged 12-17 years), diagnosed with DSM-IV AN (307.1) were evaluated in a child and adolescent psychiatric department of a major university hospital from December 1997 to August 2008. In addition, 40 healthy adolescents of the same age with normal weight were examined. In patients with AN, 34.7% had a pericardial effusion (PE) which was clinically silent. In contrast, none of the controls presented with PE (p < 0.001). No differences across AN subtypes were observed. Patients with PE showed significantly lower body mass index (BMI) (p = 0.016) than patients without PE. They had more prominent low-T3 syndrome (p = 0.003) and longer duration of hospitalisation (p = 0.008) after controlling for BMI at admission. Remission of PE was observed in 88% of the patients after weight restoration. Left ventricular end-diastolic and end-systolic dimensions in AN were significantly lower than in controls (p < 0.001). There were no differences in interventricular septum thickness, posterior wall thickness and fractional shortening. This report indicates that adolescents with AN show cardiac abnormalities in comparison to healthy young women. Furthermore, PE is a frequent cardiac complication in patients with AN and it is associated with BMI, low T3 serum levels and duration of hospitalisation.

Food Deprivation Sensitizes Pain Perception

While food deprivation has known effects on sympathovagal balance, little is known about hunger’s influence on the perception of pain. Since autonomic activities influence many cognitive and emotional processes, this suggests that food deprivation should interact with the perception of pain. This study analyzed the possible effects of short-term food deprivation on pain sensitivity in healthy female participants. This study was comprised of 32 healthy female participants who underwent a 48-hr inpatient hospital investigation. Prior to testing, heart rate and heart rate variability were assessed. After a standardized breakfast, day 1 measurements were taken. Food intake was then not allowed again until the following evening for 22 participants (experimental group), while 12 participants were served standard meals (control group). Pain threshold and tolerance were assessed at 10:00 a.m. on both days using a pressure algometer. Additionally pain experience was examined. Food deprivation significantly reduced pain thresholds and tolerance scores in the experimental group. Additionally, the sympathovagal balance changed, characterized by a decrease in parasympathetic activation. Higher vagal withdrawal after food deprivation was associated with higher pain sensitivity in the experimental group. Furthermore, perceived unpleasantness and pain intensity increased for threshold and tolerance stimuli in the experimental group. We conclude that short-term food deprivation sensitized pain perception in healthy females. An imbalance in sympathovagal activation evoked by food deprivation accounted for this effect. Our results might be a pathogenic mechanism for the development of emotional difficulties associated with disturbed eating behavior.

Heart rate variability in anorexia nervosa and the irritable bowel syndrome

BACKGROUND

Many studies have reported disturbances of heart rate variability (HRV) in patients with psychosomatic disorders such as anorexia nervosa (AN) and the irritable bowel syndrome (IBS). However, both have never been directly compared.

METHODS

We compared HRV in AN (n = 21) and in IBS (n = 21) (all females) with 42 healthy female control subjects who were matched for age and in IBS to body mass index (BMI). Recovery periods between different cardiac load tests were compared with baseline recordings and tilt test to estimate time [mean successive difference (MSD)] and frequency domain (Goldberger dimension, frequency of HF peak location and HF power, log HF power) values and to assess general reactivity of the autonomic nervous system (ANS).

KEY RESULTS

Significantly longer inter-beat intervals (IBIs) in AN patients and lower values of MSD in IBS patients were found in comparison with respective controls; both were independent from experimental conditions and are found in baseline recordings only. Both effects were independent of age and BMI. We also demonstrate a significant relationship between age, BMI and some HRV parameters.

CONCLUSIONS & INFERENCES

Opposite autonomic patterns were found in AN and IBS: stronger vagal withdrawal in IBS and weaker vagal inhibition in AN patients. Records made at rest and without any autonomic load may be representative for assessment of ANS function. Age and BMI should be taken into consideration during assessment of HRV data.

Abnormal diurnal patterns of salivary α-amylase and cortisol secretion in acute patients with anorexia nervosa

OBJECTIVES

The evidence that the activity of the sympathetic nervous system (SNS) is decreased in acute anorexia nervosa (AN) is not consistent. Therefore, we aimed to assess the SNS basal activity in malnourished AN patients through the measurement of diurnal salivary levels of α-amylase, whose secretion is regulated by the SNS. As secondary aim, we measured also salivary cortisol.

METHODS

Eight symptomatic female patients with restrictive AN and eight age-matched healthy women underwent saliva sample collection at awakening and over the day. α-amylase and cortisol were assayed by ELISA method.

RESULTS

In both patients and controls, saliva α-amylase levels significantly decreased during 60 min after awakening and then progressively rose towards the afternoon/evening. AN patients exhibited significantly reduced levels of the salivary enzyme with a significant decrease in its overall diurnal secretion and a dysregulated secretory pattern. As compared to control women, AN patients exhibited significantly enhanced levels of salivary cortisol at awakening, an enhanced and advanced cortisol secretion after awakening but no significant change in the overall diurnal secretion of the salivary hormone.

CONCLUSIONS

These results suggest that the activity of the SNS, evaluated through the assessment of the diurnal secretion of salivary α-amylase, is impaired in the acute phase of AN whereas the cortisol awakening response is enhanced.

Heart rate variability as a measure of cardiac autonomic function in anorexia nervosa: a review of the literature

OBJECTIVE

Patients with anorexia nervosa (AN) exhibit a wide range of autonomic system disturbances; these patients have also high mortality risk due to cardio-vascular complications. Origin and pathogenesis of such changes are not absolutely clear.

METHODS

Relevant publications were drawn from PUBMED using the keywords 'anorexia nervosa' AND 'autonomic'. Fifty two abstracts were identified and screened for papers that measured the state of autonomic regulation by means of analysis of heart rate variability either during 24-hour electrocardiography (ECG) monitoring or during a short-term laboratory test. Studies selected were analysed for the number of patients included, the presence and quality of control groups, gender, age and body mass index (BMI) of patients, type of AN as well as methods used to determine heart rate variability (HRV).

RESULTS

Twenty papers on HRV in patients with anorexia were identified and analysed, revealing three distinct positions regarding changes of autonomic nervous system (ANS) functions in patients with AN. The majority of papers identified parasympathetic/sympathetic imbalance with parasympathetic dominance and decreased sympathetic modulation; others could not replicate these findings, but instead described sympathetic dominance; finally a group of papers could not identify any autonomic differences in comparison to control samples. We conclude that in its current state of analysis HRV may not be suitable for routine assessment of ANS function in AN patients but rather remains a research tool.

Increased QT variability in patients with anorexia nervosa--an indicator for increased cardiac mortality?

OBJECTIVE

Increased mortality in anorexia nervosa is associated with autonomic dysfunction and prolongation of the QT interval. In this study, we examined the relative importance of repolarization abnormalities and vagal modulation of heart rate. In particular, we hypothesized that patients with anorexia nervosa show increased QT interval variability, particularly since this measure has been shown to correlate with serious cardiac arrhythmias.

METHOD

We assessed linear and nonlinear heart rate variability (HRV) parameters as well as measures of QT variability in 20 female patients with anorexia nervosa and 20 controls. In patients, parameters were correlated with serum electrolytes.

RESULTS

QT variability was significantly increased in the patient group and correlated negatively with serum potassium concentrations. HRV measures showed a shift of autonomic balance towards vagal predominance.

DISCUSSION

The increase in QT variability might at least in part account for the higher risk of cardiac arrhythmias in patients with anorexia nervosa. Once validated in a prospective study design, parameters of QT variability might serve as surrogate markers for arrhythmia risk stratification in anorexia nervosa. Supplementation with potassium might normalize QT variability abnormalities.

Malnutrition and hemodynamic status in adolescents hospitalized for anorexia nervosa

OBJECTIVE

To determine the effects of malnutrition on hemodynamic status of adolescents hospitalized for anorexia nervosa.

DESIGN

Longitudinal observational study.

SETTING

Tertiary care pediatric hospital. Patients Thirty-eight adolescents with anorexia nervosa, aged 13 to 21 years, with a mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) of 15.9 (1.8). Intervention Subjects received standard care, including bed rest and graded nutritional therapy. A subsample of subjects (n=19) returned 11 to 57 weeks following hospitalization for a second cardiac evaluation.

MAIN OUTCOME MEASURES

Results from a 15-lead electrocardiogram, echocardiogram, treadmill stress test, and spinal bone mineral density measurement.

RESULTS

On admission, 26 subjects (68%) had sinus bradycardia. Bradycardia was less common in participants with a longer duration of illness (P=.04). Left ventricle mass was lower than predicted for age (Z score<-1.0) in 11 subjects (31%). Exercise tolerance was normal by all measures. Both heart rate and QT interval were predictors of spinal bone mineral density. In those who returned for follow-up, absolute measures of left ventricle mass did not change (P=.27). However, the corresponding Z scores declined over time (mean [SD] change, -0.9 [1.3]; P=.02).

CONCLUSIONS

In acutely malnourished adolescents with anorexia nervosa, few truly pathologic cardiac findings were identified. Sinus bradycardia was observed in most cases. Mild reductions in left ventricle mass and left ventricle function were seen both at baseline and at follow-up, suggesting early sparing of cardiac muscle in the face of moderate malnutrition as well as a relative delay of cardiac muscle restoration. The association of hemodynamic status with altered spinal bone mineral density emphasizes the range of systems affected by malnutrition in anorexia nervosa.