Heart rate power spectrum analysis of autonomic dysfunction in adolescents with anorexia nervosa

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.

Is there a link between stress and immune biomarkers and salivary opiorphin in patients with a restrictive-type of anorexia nervosa?

Objectives: Opiorphin is a salivary peptide with analgesic and antidepressant properties. Its relationship with the hypothalamic-pituitary-adrenal, autonomic nervous and immune systems may provide understanding of chronic stress, especially in anorexia nervosa (AN). This study investigated a possible correlation between opiorphin and stress/immune biomarkers, cortisol, salivary alpha-amylase (sAA) and secretory immunoglobulin A (sIgA), in saliva of patients with restrictive-type AN.Methods: A case-control clinical trial was conducted in 92 AN patients (+75 healthy controls). Unstimulated salivary samples were taken during the acute stage of AN, measurements of cortisol, sAA, sIgA and opiorphin were performed with a quantitative assay (enzyme-linked immunosorbent assay, P < 0.05).Results: AN patients displayed an increase in cortisol (P < 0.001) and sIgA (P < 0.001) but not in sAA (P = 0.279) levels. Distinct correlation between these two parameters and body-weight indexes were observed. Opiorphin levels were neither correlated to stress and immune biomarkers, nor to salivary flow rate.Conclusions: The effect of stress responses can be reliably assessed in saliva in AN patients. The difference between sIgA and cortisol indicate that they can both be used for mental stress assessment in saliva. Modulation of opiorphin by chronic stress was not confirmed. Unchanged sAA indicates a partial adaptation of human organism to severe condition during malnutrition.

Stress hormones and eating disorders

AIMS

The aim of this paper is to emphasize the role of stress processes in the aetiology of eating disorders.

METHODS

We have examined the literature for evidence that people with eating disorders might exhibit markers of stress and show signs of the "maltreated ecophenotype".

RESULTS

Early adversity is more common among people with binge eating behaviours. The secondary effects of malnutrition, which are mostly marked in anorexia nervosa, may be an added stressor that could also contribute to the stress related phenotype. People with eating disorders have anomalies in brain structure, reward and punishment sensitivity, and the balance between HPA and SMA function. These may be potential targets for treatment.

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.

Salivary alpha-amylase, secretory IgA and free cortisol as neurobiological components of the stress response in the acute phase of anorexia nervosa

Objectives One novel hypothesis of the pathogenesis of anorexia nervosa (AN) is the possible role of mental stress in hyperactivity of the autonomic nervous system (ANS) and of the hypothalamic-pituitary-adrenal (HPA) axis. Two components of stress response - salivary alpha-amylase (sAA) and free cortisol - have been proposed. They can be determined in saliva, which closely reflects their concentrations in plasma. The purpose of this study was to measure salivary free cortisol, sAA and their correlation to secretory IgA (sIgA) of patients with AN in comparison to the average population. Methods A controlled clinical trial was designed for a matched group of 47 AN patients and 54 healthy individuals. After clinical examination, unstimulated salivary samples were taken during the acute stage of AN (BMI < 15 kg/m(2)) in the first week of hospitalisation. An enzyme-linked immunosorbent assay (ELISA) suitable for measuring sAA, sIgA and free cortisol were used. Results Anorexic patients exhibited disturbances in sAA secretion, and significantly increased cortisol and sIgA levels with a distinct correlation between these two parameters. Conclusions The behaviour of cortisol, sAA and sIgA levels can be assessed as an effect of stress reaction among AN patients with hyperactivity of the HPA axis and ANS dysregulation. The effect of stress response can be assessed reliably in saliva.

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.

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.

Autonomic dysfunction responses to head-up tilt in anorexia nervosa

PURPOSE

Autonomic dysfunction of the cardiovascular system in anorexia nervosa (AN) was reported not only in the rest position, but also in the standing position in some previous studies, which might contribute to cardiac complications such as lethal arrhythmia. However, there has not been sufficient literature in this issue. Therefore, we performed a head-up tilt test, and compared the changes after tilting in indices of autonomic function between AN patients and healthy subjects by heart rate variability (HRV) and blood pressure variability (BPV).

METHODS

The subjects were 21 females with AN and 30 age-matched healthy women. A head-up tilt test was performed following the protocol recommended by the American Heart Association. Blood pressure and heart rate data were collected for 10 min before and after tilting. In the frequency analysis, the powers of low-frequency (LF) and high-frequency (HF) components were calculated by a fast Fourier transformation.

RESULTS

Regarding interactions between groups and head-up tilting, the head-up tilting-induced reduction of the HF component of HRV was significantly greater in the AN group. In addition, increases in the LF/HF of HRV and the LF component of BPV after head-up tilting were significantly smaller in the AN group.

CONCLUSIONS

Regardless of the posture, changes in HF and LF/HF of HRV and LF of BPV in AN patients suggested the presence of autonomic insufficiency.

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.

Asymmetry of salivary cortisol and α-amylase responses to psychosocial stress in anorexia nervosa but not in bulimia nervosa

BACKGROUND

The stress response involves the activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS). As a role for stress in determining of the onset and the natural course of eating disorders (EDs) has been proposed, the study of the psychobiology of the stress response in patients with anorexia nervosa (AN) and bulimia nervosa (BN) should be helpful in understanding the pathophysiology of these disorders. The two neurobiological components of the stress response can be easily explored in humans by the measurement of salivary cortisol and α-amylase response to a stressor. Therefore, we assessed salivary cortisol and α-amylase responses to the Trier Social Stress Test (TSST) in symptomatic patients with AN and BN compared to healthy controls.

METHOD

Seven AN women, eight BN women and eight age-matched healthy females underwent the TSST between 1530 and 1700 h. Salivary cortisol and α-amylase levels were measured by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared to healthy women, AN patients showed a normal cortisol response to the TSST, although this occurred at significantly increased hormone levels, and an almost complete absence of response of α-amylase. BN women, however, exhibited enhanced pre-stress levels of salivary α-amylase but a normal response of the enzyme and cortisol to the TSST.

CONCLUSIONS

These findings demonstrate, for the first time, the occurrence of an asymmetry between the HPA axis and SNS components of the stress response in the acute phase of AN but not in BN. The pathophysiological significance of this asymmetry remains to be determined.

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.

Irreversibility of cardiac autonomic dysfunction in female adolescents diagnosed with anorexia nervosa after short- and long-term weight gain

Anorexia nervosa (AN) patients may present with cardiac autonomic system dysfunction. Power spectral analysis of heart rate variability (HRV) is a reliable noninvasive examination for the quantitative assessment of the central sympathovagal interaction that modulates cardiovascular autonomic function. In the present study, HRV parameters were assessed in female adolescent AN inpatients in the malnourished phase at admission, at discharge when achieving weight restoration, and 24-36 months after discharge, when considered remitted. Nineteen normal-weight female controls were similarly assessed. Spectral analysis of HRV was done with the fast Fourier transform algorithm. At admission and discharge, patients underwent routine laboratory examinations and responded to questionnaires assessing eating-related preoccupations, behaviors, and personality attributes, depression and anxiety. Compared with the controls, AN patients had significantly lower heart-rate and HRV, lower total power and low frequency components, elevated high frequency components, and decreased low to high frequency power ratio as assessed with the power spectral analysis at all three evaluation points. These disturbances were not correlated with the baseline laboratory and psychometric measures. Our preliminary findings suggest that female adolescent AN inpatients may have a cardiovascular autonomic dysfunction in the form of vagal abnormality present not only in malnourished patients, but also persisting following short-term and long-term weight restoration.

Habitual response to stress in recovering adolescent anorexic patients

OBJECTIVE

Although previous research has investigated the stress response in acutely anorexic patients, there is currently little research addressing this response in recovering adolescent anorexic girls. Therefore, this study investigated partially and fully weight-restored anorexic adolescent girls' psychological and physiological response to a standardized stressor.

METHODS

We measured the heart rate and affect of 17 adolescent recovering anorexic patients and 40 healthy age-matched controls during two conditions of the Stress Induced Speech Task (SIST): Free Association and Stress Task. Recovering patients were either partially or fully weight-restored.

RESULTS

Compared to the controls, the recovering anorexic girls reported greater overall habitual psychological distress and higher levels of negative affect during the standardized stressor. However, recovering patients did not show a muted heart rate response during the stressor. Neither recovering anorexics nor controls demonstrated a correspondence between heart rate and positive or negative affect.

DISCUSSION

Although the physiological stress response of recovering adolescent anorexic patients was similar to controls, the psychological response of partially and fully weight-restored anorexic adolescents appears similar to that of acutely anorexic adolescents. Treatment implications are discussed in terms of the persistence of negative affect and treatment resistance.

Heart rate variability as a measure of autonomic nervous system function in anorexia nervosa

BACKGROUND AND HYPOTHESIS

Alteration in sympathovagal balance may be a mechanism of increased cardiovascular mortality and sudden death of patients with anorexia nervosa. This study was undertaken to characterize cardiac autonomic control in patients with anorexia nervosa by means of heart rate variability analysis.

METHODS

Heart period variability by 24-h Holter recording was evaluated in 13 young women with anorexia nervosa, 10 constitutionally thin women, and 10 women of normal weight.

RESULTS

High-frequency power, a measure of parasympathetic modulation of heart rate, and all-time domain measures of heart rate variability were higher in patients with anorexia nervosa than in thin women and in those of normal weight. Thin women showed lower values of total power and of most components of power spectrum.

CONCLUSIONS

Our data demonstrate an increased vagal tone in young women with anorexia nervosa. The marked increase in parasympathetic activity, not in response to an increase in sympathetic activity, could be detrimental and may contribute to the higher cardiovascular mortality of these patients.

Nonlinear analysis of heart rate variability in patients with eating disorders

Patients with anorexia nervosa or bulimia nervosa often have signs of autonomic dysfunction potentially deleterious to the heart. The aim of this study was to ascertain the nonlinear properties of heart rate variability in patients with eating disorders. A group of 33 women with eating disorders (14 anorexia, 19 bulimia) and 19 healthy controls were included in the study. Conventional time- and frequency-domain heart rate variability measurements, along with nonlinear heart rate variability measurements including the short-term fractal scaling exponent alpha and approximate entropy (ApEn) were calculated. Anorexia nervosa patients exhibited decreased values of alpha, while bulimia nervosa patients had decreased values of ApEn. Low-frequency heart rate variability was decreased in patients with anorexia. In conclusion, these results are compatible with the view that a more severe alteration of cardiac autonomic function is present in anorexia than in bulimia.

Heart rate and blood pressure variability and baroreflex sensitivity in patients with anorexia nervosa

OBJECTIVE

Anorexia nervosa (AN) is considered to have a significant risk for sudden death because of cardiac complications, and abnormalities of the autonomic nervous system might be a cause of cardiac dysfunction. The aim of this study was to investigate autonomic nervous system function in AN patients by analyzing heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS).

METHODS

The subjects were 32 AN patients without other psychiatric comorbidities and 37 healthy controls. Beat-to-beat R-R interval and systolic blood pressure recorded in the supine position were analyzed using power spectral analysis and cross-spectrum analysis to quantify the frequency domain properties of HRV, BPV, and BRS. In addition, detrended fluctuation analysis was used to quantify the fractal correlation properties from the scaling exponent alpha1 of HRV.

RESULTS

High frequency power and total power of HRV and BRS were significantly higher in AN patients and low frequency power of BPV, low frequency/High frequency ratio of HRV, and the scaling exponent alpha1 of HRV were significantly lower in AN patients, compared with controls.

CONCLUSIONS

These findings suggest that AN patients have reduced cardiovascular sympathetic nervous responsiveness, increased parasympathetic nervous responsiveness, and increased complexity of the interbeat interval time series compared with healthy controls. Regarding the relationship to prognosis of AN, the study showed conflicting results, and further prospective studies are needed to determine if these results are related to high mortality in AN patients.

Heart failure in anorexia nervosa: case report and review of the literature

OBJECTIVE

To report the presentation and causes of heart failure complicating anorexia nervosa (AN).

METHOD

Report of a case of heart failure occurring in a patient with AN and a review of the literature.

RESULTS

A 56 year old woman with a 25 year history of AN binge-purge subtype experienced increasing shortness of breath on exertion, orthopnea, and swelling of the ankles. Investigations revealed a reduced left ventricular ejection fraction. A diagnosis of heart failure caused by severe prolonged protein-calorie malnutrition was made. She was treated with a diuretic, a beta adrenergic blocker and an angiotension enzyme inhibitor. Her cardiac function returned to normal after a year of refeeding. Protein-calorie malnutrition, ipecac toxicity, and deficiencies of thiamine, phosphorus, magnesium, and selenium have been reported to cause heart failure in patients with AN.

DISCUSSION

If shortness of breath occurs in AN it may be a symptom of heart failure. The diagnosis is further suggested by increased jugular venous pressure, increasing shortness of breath on exertion, and pulmonary crepitations at the bases of the lungs on physical examination. The chest x-ray usually shows pulmonary venous redistribution, the electrocardiogram may be normal, and the echocardiogram should document a reduced left ventricular ejection fraction. Standard medical therapy for heart failure should be started. In addition, a history of ipecac use should be taken, deficiencies should be corrected, and weight restoration can reverse cardiac abnormalities.

Changes of pain perception, autonomic function, and endocrine parameters during treatment of anorectic adolescents

OBJECTIVES

The underlying mechanisms of reduced pain perception in anorexia nervosa (AN) are unknown. To gain more insight into the pathology, the authors investigated pain perception, autonomic function, and endocrine parameters before and during successful treatment of adolescent AN patients.

METHOD

Heat pain perception was assessed in 15 female adolescent AN patients and matched controls. Results were correlated with autonomic and endocrine parameters (free triiodothyronine, free cortisol). Autonomic function was studied using heart rate variability and pupillary light reflex assessment. To investigate the influence of therapy on these parameters, data were obtained at three different time points.

RESULTS

Heat pain thresholds were significantly increased in the acute state and decreased after weight had been regained for 6 months. Similarly, an increased parasympathetic tone was present in the acute state only. The relative amplitude of the pupillary light reflex showed a positive correlation to pain thresholds over time and predicted disease progression. In addition, the authors found a negative correlation between increased pain thresholds and low free cortisol.

CONCLUSION

Increased pain thresholds are associated with increased parasympathetic tone and a hypothyroid state in AN. This may either indicate common central mechanisms or suggest a causative interaction.

Linear and non-linear heart rate variability measures in chronic and acute phase of anorexia nervosa

Previous results on heart rate variability (HRV) analysis in anorexia nervosa (AN) include some apparently conflicting data. In order to find out the reason for different results and to improve understanding of autonomic control in AN we compare HRV in acute and chronic AN. Spectral powers, fractal scaling exponent and sample entropy were computed from 24 h RR series derived from Holter ECG recordings in 17 anorexic patients, nine chronic and eight healthy women. We found that all linear and non-linear HRV measures change in different direction in acute and chronic AN. Acute AN is characterized by decreased HR and increased HRV. In chronic AN, HR is increased, HRV reduced and the difference between awake and sleeping values is high. HRV measures are associated with body mass index only in chronic AN. As HRV measures are significantly different between acute and chronic AN, we propose that HRV analysis might provide additional data in clinical practice.

Measuring change in parotid gland size: test-retest reliability of a novel method

BACKGROUND

There is currently no convenient method for measuring parotid gland hypertrophy, a common condition among patients with bulimia nervosa (BN) and anorexia nervosa (AN).

OBJECTIVE

To develop a technique for reliably estimating change in parotid gland size.

METHODS

A method for measuring facial width as a surrogate marker of parotid gland size was developed using calipers to measure between defined reference points located on the parotid gland region. The method was tested for reliability when performed by a single operator and used to determine face width measurements of 15 control subjects.

RESULTS

Face width measurements were reliable when performed by a single operator. Face width measurements of control subjects ranged from 9.1 cm to 15.3 cm.

DISCUSSION

The caliper method of measuring changes in parotid size is a novel method of measurement of parotid hypertrophy. It is quick, non-invasive and inexpensive and is highly reliable in the hands of a single operator.

The dearth of psychological treatment studies for anorexia nervosa

OBJECTIVE

Anorexia nervosa (AN) was first described more than 130 years ago, yet few psychological treatments have been formally studied. Our objective was to review the available studies to understand whether these may highlight directions for future investigation.

METHOD

Medline and PsycINFO were consulted to identify relevant treatment studies. Twenty psychotherapy treatment studies were identified for review. These were divided in terms of patient age (adolescent vs. adult) and type of study (uncontrolled vs. controlled).

RESULTS

Without exception, adolescent studies (uncontrolled or controlled) involved the parents or family in the treatment. The adult studies were much more varied in terms of treatments that were compared. Most studies were statistically underpowered and only one utilized manualized treatments. More recent investigations have attempted to remedy these methodologic shortcomings.

DISCUSSION

The review highlights the effectiveness of one particular treatment modality for adolescents, but emphasizes the compelling need for further and larger systematic investigation into treatments for both adolescent and adult AN.

Refeeding normalizes the QT rate dependence of female anorexic patients

We postulated that dynamic alterations in QT interval adaptation could characterize patients with anorexia nervosa (AN) and could be restored after weight gain. To assess ventricular repolarization features, we evaluated the QT dynamicity along RR intervals from 24-hour electrocardiographic data of patients with AN before and after refeeding. Ten young women with AN (19 +/- 3 years) were included in the study. The QT/RR slope was found significantly enhanced compared with normals (-1.82 +/- 0.62 vs -1.40 +/- 0.30; p < 0.05). This slope returned to normal range values after refeeding. The QT/RR slope was significantly correlated with the body mass index (r = 0.59; p < 0.007) in the patient group.

Physical and psychological factors influencing heart rate variability in anorexia nervosa

OBJECTIVE

The aim of this study was to determine which physical and psychological factors influence the autonomic nervous system (ANS) of patients with anorexia nervosa (AN).

METHODS

The subjects were 14 AN patients and 12 healthy controls. Beat to beat heart rate variability recorded in a supine position with a controlled respiratory rate of 15/min, was analyzed using power spectral analysis. Symptoms of anxiety and depression were assessed by State and Trait Anxiety Inventory and Zung's Self-rating Depression Scale respectively.

RESULTS

Anxiety had a significant negative correlation with the ANS of AN patients. The illness duration times body mass index (BMI), a measure of sustained extreme loss of weight, was also significantly associated with changes in the ANS of AN patients.

CONCLUSION

Although the ANS is influenced by various factors, sustained extreme loss of weight seems to be more influential factor in AN patients.

Effects of anorexia nervosa on clinical, hematologic, biochemical, and bone density parameters in community-dwelling adolescent girls

OBJECTIVE

Anorexia nervosa (AN) is an eating disorder that leads to a number of medical sequelae in adult women and has a mortality rate of 5.6% per decade; known complications include effects on hematologic, biochemical, bone density, and body composition parameters. Few data regarding medical and developmental consequences of AN are available for adolescents, in particular for an outpatient community-dwelling population of girls who have this disorder. The prevalence of AN is increasing in adolescents, and it is the third most common chronic disease in adolescent girls. Therefore, it is important to determine the medical effects of this disorder in this young population.

METHODS

We examined clinical characteristics and performed hematologic, biochemical, hormonal, and bone density evaluations in 60 adolescent girls with AN (mean age: 15.8 +/- 1.6 years) and 58 healthy adolescent girls (mean age: 15.2 +/- 1.8 years) of comparable maturity. Nutritional and pubertal status; vital signs; a complete blood count; potassium levels; hormonal profiles; bone density at the lumbar and lateral spine; total body, hip, and femoral neck (by dual-energy x-ray absorptiometry) and body composition (by dual-energy x-ray absorptiometry) were determined.

RESULTS

All measures of nutritional status such as weight, percentage of ideal body weight, body mass index, lean body mass, fat mass, and percentage of fat mass were significantly lower in girls with AN than in control subjects. Girls with AN had significantly lower heart rates, lower systolic blood pressure, and lower body temperature compared with control subjects. Total red cell and white cell counts were lower in AN than in control subjects. Among girls with AN, 22% were anemic and 22% were leukopenic. None were hypokalemic. Mean age at menarche did not differ between the groups. However, the proportion of girls who had AN and were premenarchal was significantly higher compared with healthy control subjects who were premenarchal, despite comparable maturity as determined by bone age. Ninety-four percent of premenarchal girls with AN versus 28% of premenarchal control subjects were above the mean age at menarche for white girls, and 35% of premenarchal AN girls versus 0% of healthy adolescents were delayed >2 SD above the mean. The ratio of bone age to chronological age, a measure of delayed maturity, was significantly lower in girls with AN versus control subjects and correlated positively with duration of illness and markers of nutritional status. Serum estradiol values were lower in girls with AN than in control subjects, and luteinizing hormone values trended lower in AN. Levels of insulin-like growth factor-I were also significantly lower in girls with AN. Estradiol values correlated positively with insulin-like growth factor-I, a measure of nutritional status essential for growth (r = 0.28). All measures of bone mineral density (z scores) were lower in girls with AN than in control subjects, with lean body mass, body mass index, and age at menarche emerging as the most important predictors of bone density. Bone density z scores of <-1 at any one site were noted in 41% of girls with AN, and an additional 11% had bone density z scores of <-2.

CONCLUSIONS

A high prevalence of hemodynamic, hematologic, endocrine, and bone density abnormalities are reported in this large group of community-dwelling adolescent girls with AN. Although a number of these consequences of AN are known to occur in hospitalized adolescents, the occurrence of these findings, including significant bradycardia, low blood pressure, and pubertal delay, in girls who are treated for AN on an outpatient basis is of concern and suggests the need for vigilant clinical monitoring, including that of endocrine and bone density parameters.

Chronotropic incompetence to exercise separates low body weight from established anorexia nervosa

Chronotropic incompetence (CI), characterized by an attenuated heart rate (HR) response to exercise could participate to the limitation of exercise capacity in anorexia nervosa (AN). Therefore, we evaluated the role of cardiac sympathetic responsiveness in AN patients. In addition, the ambulatory value of autonomic control using spectral analysis of heart rate variability (HRV) was determined and correlated to maximal exercise performance. Twenty-two patients hospitalized for weight loss and suspicion of AN were included in the study. All performed a symptom-limited exercise test with measurement of gas exchange for chronotropic response to exercise evaluation. Holter ECG recordings allowed daytime and night-time spectral domain HRV analysis in order to evaluate the alteration of sympathetic control of HR in free-living conditions. CI defined as a failure to achieve 80% of heart rate reserve (%HRR) was observed in 13 (59%) patients (CI+). This group presented a higher body mass deficit than the group without CI (CI-; -35.1 +/- 8.7% versus -26.1 +/- 10.7%; P<0.05). Obviously, patients with a lower body mass index (BMI < 16 kg m(-2), n = 14) revealed a more severe limitation to maximal exercise with a lower peak HR, a lower peak Vo(2), and a lower maximal O(2) pulse (P<0.05). BMI was significantly correlated to peak Vo(2), maximal HR, and %HRR achieved at peak exercise. Daytime HRV parameters reflecting the sympathetic autonomic equilibrium (LF nu, LF/HF ratio) were significantly lower in CI+ patients. Blunted sympathetic response to maximal exercise is frequent and correlated to weight deficit. The present data suggest a major autonomic derangement in AN characterized by a cardiac sympathetic withdrawal.

Alteration of the QT Rate Dependence in Anorexia Nervosa

Myocardial repolarization has been evaluated in patients with anorexia nervosa (AN) with conflicting results. The authors postulated that dynamic alterations in QT interval adaptation could characterize these patients. This study compared QT dynamicity along RR intervals from 24-hour ECG data of patients with and without AN. Twenty-five patients (23 women) fulfilling the Diagnostic and Statistical Manual (DSM IV) criteria for AN were included in the study. All underwent 24-hour ECG Holter recordings, allowing QT and RR measurements, and heart rate variability (HRV) analysis in free-living conditions. A group of 25 sex- and age-matched healthy subjects served as controls. Compared with controls, AN patients presented with relative bradycardia, more particularly during night periods but neither mean QT nor corrected mean QT length (calculated using Bazett formula) over the 24 hours of monitoring differed. However, QT/RR slope was found significantly enhanced compared with normals (-2.00 +/- 0.53 vs - 1.42 +/- 0.40) (P = 0.006): QT length related to heart rate was found longer for a heart rate <55 beats/min in AN. Mean 24-hours QT length appears unaltered in AN in the absence of electrolytic disorders. However, the QT/RR relationship was enhanced reflecting the specific autonomic imbalance encountered in this population. The clinical implications of such findings need to be discussed since an equivalent enhancement of QT/RR slope has been described after myocardial infarction in patients presenting life-threatening ventricular arrhythmias.

Physiological regulation and infantile anorexia: a pilot study

OBJECTIVE

To examine whether infantile anorexia is associated with physiological dysregulation.

METHOD

This study included eight toddlers with infantile anorexia and eight healthy eaters matched for age, race, socioeconomic status, and gender. Physiological measures of heart period and respiratory sinus arrhythmia were assessed across three different situations: mother-toddler interaction, toddler-stranger interaction, and toddler left alone with a toy while mother and stranger talked to each other at the other side of the room.

RESULTS

Across all three situations, toddlers with infantile anorexia showed significantly shorter heart periods (i.e., faster heart rates) than controls (p <.05). In addition, as social demand decreased from episode 2 to episode 3, control toddlers exhibited an increase in respiratory sinus arrhythmia, whereas toddlers with infantile anorexia showed a decrease in respiratory sinus arrhythmia (p <.001).

CONCLUSIONS

Toddlers with infantile anorexia showed consistently shorter heart periods and were less adaptive in their physiological regulation than controls. Such physiological dysregulation may constitute a tendency for less optimal internal homeostatic regulation of feeding in toddlers with infantile anorexia.

Electrogastrography abnormality in eating disorders

Eating disorders are common psychiatric disorders in young women. The aim of the present study was to evaluate the gastric electrical activity of patients with eating disorders and its relation to their symptoms. The electrogastrography (EGG) was performed before and after a water load test for outpatients with eating disorders (n = 36; 14 anorexia nervosa, 14 bulimia nervosa, eight eating disorder not otherwise specified) and healthy women (n = 19). A structured interview (Eating Disorder Examination) was used to assess clinical symptoms. The percentage of normal gastric myoelectrical power was significantly smaller in the eating disorder patients (44.5% vs 74.2%; P < 0.05), while the percentage of bradygastric power was significantly greater, both before and after the water load test compared with the control subjects (30.4% vs 10.4%; P < 0.05). In addition, moderate correlation was found between the duration of illness and the percentage of bradygastria (P < 0.05). In conclusion, it is suggested that longstanding abnormal eating in patients with eating disorders may induce disturbances to gastric motor function, resulting in their abnormal, eating-related behavior, and form a symptomatic vicious circle. The EGG may be a promising method for determining the pathophysiology of eating disorders and for developing effective therapeutic approaches.

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

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.

Cardiac autonomic dysfunction in AIDS is not secondary to heart failure

OBJECTIVE

Heart rate variability (HRV) is a marker of cardiovascular autonomic tone, and is also known to be reduced in association with cardiac dysfunction. Abnormal autonomic function tests are common in HIV infected individuals, but the contribution of heart disease to such findings is not known. Spectral analysis of heart rate variability is a sensitive technique for measurement of cardiovascular autonomic function, which also allows differential assessment of parasympathetic and sympathetic components. The aim of this study was to characterise the nature of autonomic dysfunction in patients with AIDS and to compare our findings with those seen in HIV seronegative patients with established heart disease.

METHODS

HRV was measured prospectively by spectral analysis in 10 subjects with dilated cardiomyopathy (age 45.7+/-6.9 years), 10 subjects with AIDS and no clinical evidence of heart disease (age 37.9+/-5.4 years), and 10 healthy HIV seronegative controls (age 41.7+/-13.9 years).

RESULTS

All components of HRV were reduced in subjects with cardiomyopathy (P<0.005), and markedly so in subjects with AIDS (P<0. 0001) compared with controls.

CONCLUSIONS

HIV infection may be associated with severe global autonomic dysfunction, which is not related to heart disease.

Eating disorders in adolescents and young adults

Eating disorders are relatively common and frequently result in medical signs and symptoms. Armed with an appreciation of the protean manifestations of these complex health problems as well as an appreciation of the biopsychosocial approach needed to help the adolescent or young adult woman recover, the primary care physician is in an excellent position to have a therapeutic role in the recovery from these chronic conditions. By recognizing the medical aspects of eating disorders, the oversimplified viewpoint of considering them as purely psychiatric disorders can be avoided. Open and consistent communication with patients, with a focus on health rather than dysfunction and mental illness, facilitates the acceptance of a comprehensive approach in which the internist, dietitian, and mental health provider all have a role.

Absent circadian variation of blood pressure in patients with anorexia nervosa

OBJECTIVE

To examine whether circadian rhythm of blood pressure (BP) is altered in patients with anorexia nervosa (AN), and if so, to determine whether it is reversible after refeeding.

STUDY DESIGN

Ambulatory BP monitoring was performed on 17 female inpatients with AN (mean age, 13.3 +/- 1.9 years) at the time of admission and serially during refeeding; 17 age-matched normal weight, normotensive female inpatients served as control subjects.

RESULTS

Patients with AN had lost an average of 23.4% +/- 11.5% of body weight before the illness. Weight after refeeding was 105.6% +/- 9. 2% of that before illness. Mean 24-hour systolic BP (SBP) (96.5 +/- 8.6 mm Hg) and diastolic BP (DBP) (53.4 +/- 5.8 mm Hg) were significantly lower in patients with AN compared with those of control subjects (SBP, 106.1 +/- 6.5 mm Hg; DBP, 60.2 +/- 5.8 mm Hg). Although awake SBP and DBP were also lower in patients with AN, asleep SBP and DBP were not statistically different from those of control subjects. Night/day BP ratio in the control group was 0.93 +/- 0.06 in systolic and 0.92 +/- 0.09 in diastolic. Those values were significantly elevated in patients with AN (systolic 1.00 +/- 0. 09 and diastolic 1.00 +/- 0.09). After refeeding, the ratio decreased to 0.88 +/- 0.09 and 0.90 +/- 0.08,respectively (both P <. 05 vs baseline).

CONCLUSIONS

In patients with AN, circadian variation of BP is absent. This reverts to normal after refeeding.

Alterations of autonomic cardiac control in anorexia nervosa

BACKGROUND

The authors investigated autonomic cardiac function in anorexia nervosa.

METHODS

Forty-eight patients, who in the present or past met the DSM-III-R criteria for anorexia nervosa, and 16 normal control subjects participated in a standardized analysis of heart rate variability during supine and standing postures.

RESULTS

Several heart rate variability parameters showed an inverse correlation to the present weight of the anorexic subjects. The values of the spectral power analyses were significantly (p < .01) lower in patients (n = 18) weighing less than 75% of ideal weight when compared to the results found in the control group; however, the heart rate variability parameters of anorexic subjects with restored weight (n = 12) did not differ from those of the control subjects.

CONCLUSIONS

The obtained results provide evidence for autonomic cardiac dysfunction in acutely ill anorexic patients. Further research is required to elucidate possible clinical consequences of these findings.