Bulimia nervosa—a primary defect in the hypthalamic–pituitary–adrenal axis?

Risk of eating disorders, changes in salivary cortisol concentrations and nutritional status of adolescents

PURPOSE

The imposition of the thin body as an ideal of beauty and the changes that occur in adolescence lead to a constant concern with adolescents' body weight, putting them at risk for eating disorders. Thus, the study sought to investigate associations between eating disorders and salivary cortisol concentrations, nutritional status and depressive symptoms in female adolescents with bulimia.

METHODS

A cross-sectional study was carried out with 1435 adolescents aged 10-19 years. The Bulimic Investigatory Test of Edinburgh (BITE) and Body Shape Questionnaire (BSQ) questionnaires were used. A follow-up study was conducted from a random selection of female adolescents diagnosed with Bulimia Development and Well-Being Assessment-(DAWBA) to assess associations with salivary cortisol concentrations and nutritional status.

RESULTS

The prevalence of body dissatisfaction among adolescents with symptoms of bulimia was 37%. There was a significant difference between salivary cortisol and bulimia (Risk Group = 0.33 ± 0.20 μg/100 ml, Diagnostic Group = 0.44 ± 0.21 μg/100 ml p = 0.040), and correlation positive between the risk of bulimia with symptoms of depression (0.355 p = 0.002) and with Body Mass Index (0.259 p = 0.028). High concentrations of salivary cortisol in bulimic adolescents may be associated with hyperactivity of the hypothalamic-pituitary-adrenal axis and depressive symptoms.

CONCLUSIONS

Nutritional status indicators cannot be used alone for the diagnosis of bulimia, since cortisol levels seem to be a reliable parameter in the identification of bulimia, provided they are used with other diagnostic criteria.

LEVEL III

Evidence obtained from cross-sectional study.

The peril and promise of sensitivity in eating disorders

Differential susceptibility, a reconceptualization of the diathesis-stress model of psychopathology, describes gene-environment interactions that reflect individual differences in responsiveness to environmental influences, both detrimental and beneficial. This model has been described metaphorically by the classification of orchids, which thrive under optimal care but wither under adverse conditions, and dandelions, which weather broad environmental circumstances but are less responsive to careful cultivation. Etiological research in the field of eating disorders has largely focused on the identification of specific behavioral phenotypes, temperamental traits, genotypes and neurobiological processes that confer risk. In this article, we propose that these putative vulnerability factors represent phenotypes and endophenotypes of a genetic predisposition towards environmental sensitivity. We assert that this sensitivity not only transmits eating disorder risk but also confers resilience, depending on the circumstances. In particular, we propose that differential susceptibility can be used as a framework to organize disparate temperamental and neurobiological findings and their complex interplay with various developmental, environmental and sociocultural influences to increase eating disorder risk and treatment responsiveness. Finally, we assert that viewed through the lens of differential susceptibility, sensitivity can be leveraged to refine our interventions and develop novel treatment and prevention strategies to support favorable outcomes for individuals with eating disorders.

Baseline cortisol predicts drunkorexia in female but not male college students

"Drunkorexia" or compensatory eating behaviors in response to alcohol consumption, resembles a subclinical eating disorder, and is a current public health concern. Eating disorders and alcohol abuse are associated with dysfunction of the hypothalamic-pituitary-adrenal axis (HPA). One index of HPA function is cortisol. As causes of drunkorexia remain elusive, the present study examined cortisol function as it relates to drunkorexia. Participants:n = 73 (49 women) college students. Method: Participants provided daytime saliva samples for cortisol analyses prior to completing an online survey measuring alcohol consumption, drunkorexia, and alcohol problems as measured by the Rutgers Alcohol Problem Index (RAPI). Results: Multiple regressions indicated that baseline cortisol significantly positively correlated with drunkorexia behaviors in women but not men. Higher baseline cortisol and aspects of drunkorexia related to alcohol problems. Conclusion: Programs educating about stress management and health risks of drunkorexia may decrease engagement in drunkorexia behaviors among college students.

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.

Residual eating disorder symptoms and clinical features in remitted and recovered eating disorder patients: A systematic review with meta-analysis

OBJECTIVE

In psychiatry, the presence of residual symptoms after treatment is linked to the definitions of remission and recovery. To identify the presence of residual eating disorder (ED) symptoms and associated non-ED clinical features in remitted and recovered EDs, the current systematic review with meta-analysis was performed.

METHOD

A systematic review was conducted on residual ED symptoms and non-ED clinical features including comorbid psychopathology, neurophysiological functioning, cognitive functioning, and quality of life in ED patients considered remitted or recovered. To examine residual ED symptoms, meta-analyses were performed while considering age, study quality, remission, and recovery criteria strictness as moderators. Sensitivity, publication bias, and heterogeneity analyses were also conducted.

RESULTS

The 64 studies selected for the systematic review underscored the presence of residual ED symptoms in anorexia nervosa (AN) and bulimia nervosa (BN), and impairments and deficits in the additional features examined. From the 64 studies, 31 were selected regarding residual ED symptoms in AN for meta-analysis. Large effect sizes indicated that remitted/recovered AN patients reported significantly lower body mass index (Hedges' g = -0.62[-0.77, -0.46]) and significantly greater symptomatology in terms of ED examination-questionnaire (Hedges'g = 0.86 [0.48,1.23]) and ED inventory (Hedges' g = 0.94[0.64,1.24]) than healthy controls, independently of remission and recovery criteria strictness, age, and study quality.

DISCUSSION

The presence of residual ED symptoms in AN is quantitatively supported, whereas the presence of residual ED symptoms in BN should be further investigated. Data on binge-eating disorder are missing. Future research should use consistent, multicomponent, and standardized comparable indicators of recovery.

Harmful effects of functional hypercortisolism: a working hypothesis

Functional hypercortisolism (FH) is caused by conditions able to chronically activate hypothalamic-pituitary-adrenal axis and usually occurs in cases of major depression, anorexia nervosa, bulimia nervosa, alcoholism, diabetes mellitus, simple obesity, polycystic ovary syndrome, obstructive sleep apnea syndrome, panic disorder, generalized anxiety disorder, shift work, and end-stage renal disease. Most of these states belong to pseudo-Cushing disease, a condition which is difficult to distinguish from Cushing's syndrome and characterized not only by biochemical findings but also by objective ones that can be attributed to hypercortisolism (e.g., striae rubrae, central obesity, skin atrophy, easy bruising, etc.). This hormonal imbalance, although reversible and generally mild, could mediate some systemic complications, mainly but not only of a metabolic/cardiovascular nature, which are present in these states and are largely the same as those present in Cushing's syndrome. In this review we aim to discuss the evidence suggesting the emerging negative role for FH.

Neuroendocrine Profile in the Night Eating Syndrome

Night eating syndrome (NES) has recently been getting more attention as a recognized eating disorder. NES is characterized by a delay in the circadian pattern of food intake, associated with morning anorexia, evening hyperphagia, awakenings from sleep with ingestion of food, depressed mood, and obesity. Although the behavioral characteristics of NES were first described in 1955, the neuroendocrine characteristics have only been described recently. Researchers have examined several hormones that appear to differ in night eaters compared to controls, including melatonin, leptin, and cortisol. Researchers have more recently examined the hypothalamic-pituitary-adrenal axis in more detail, with emphasis on corticotrophin releasing hormone. Further studies have examined ghrelin, growth hormone, prolactin, and IGF-1, with differences observed in the circadian pattern of these hormones in those with NES compared to controls. Despite increasing interest in the neuroendocrine profile of night eating behavior, the biological basis of NES is still not well understood.

Short-term exercise combined with Acipimox administration induces an increase in plasma ACTH and its subsequent fall in the recovery phase in bulimic women

OBJECTIVE

Free fatty acids (FFA)-adrenocorticotropin (ACTH) feedback loop between adipose tissue and the hypothalamic-pituitary centers in the brain has been suggested to be affected by the exercise and by administration of anti-lipolytic drugs. Also leptin may be affected by exercise. Dysfunction of FFA-leptin-ACTH secretion might be involved in binge eating and subsequent purging as is the case in bulimia nervosa (BN).

METHODS

In the present single-blind, randomized study, we explored responses of plasma ACTH, leptin and FFA concentrations to exercise (45 min, 2 W/kg of lean body mass [LBM]) with Acipimox (Aci), an anti-lipolytic nicotinic acid analog, or placebo randomly received in nine women with BN and nine healthy women.

RESULTS

The exercise with Aci administration resulted in plasma ACTH (p<0.001) and leptin increase higher in BN patients and a decrease in the plasma FFA levels in both groups. The falling of plasma ACTH (p<0.01) levels in the post-exercise recovering phase (90-minute) with Aci administration is more expressed in BN patients. The exercise induced an increase in plasma ACTH (p<0.05) and FFA levels and a decrease in the plasma leptin level in both groups.

CONCLUSIONS

We demonstrated that the Aci-induced elevation in plasma ACTH (p<0.001) levels after the exercise higher in BN patients and that the falling of plasma ACTH (p<0.01) levels in the post-exercise recovering phase (90-minute) with Aci administration is suppressed only in BN patients, while Aci increased plasma leptin levels in this recovering phase more in BN patients. Therefore, these observations led us to suggesting that FFA-leptin-ACTH are involved in the dysregulation of neuroendocrine profile in this syndrome and that Aci affects a FFA-independent mechanism. In conclusion, Aci can be considered acceptable in the treatment of eating disorders, and it may also serve as an alternative low-dose dexamethasone suppression test (LDDST) in these patients.

TRIAL REGISTRATION

Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12612000309886.

Regulating satiety in bulimia nervosa: the role of cholecystokinin

PURPOSE

Individuals with bulimia nervosa (BN) report altered perceptions in hunger, fullness, and satiety. This article reviews the role of cholecystokinin (CCK), a satiety-producing hormone, in the regulation of binge eating in those who suffer from BN.

CONCLUSION

Studies have shown that CCK is decreased in individuals with BN when compared with healthy controls. Decreased CCK functioning may contribute to impaired satiety and thus binge eating in this patient population. Depending on the macronutrient composition of food choices, CCK release can be differentially influenced. For instance, protein is a potent stimulator of a CCK response. Eating more protein-rich meals increases the release of CCK, increasing satiety and ending a meal.

PRACTICE IMPLICATIONS

Knowledge of CCK functioning and the utility of manipulating the macronutrient composition of meals may inform standard behavioral treatment strategies for those who suffer from BN.

Neurobiological and psychopathological variables related to emotional instability: a study of their capability to discriminate patients with bulimia nervosa from healthy controls

OBJECTIVE

To analyze the capability of a set of neurobiological and psychopathological variables to discriminate bulimia nervosa (BN) patients from healthy controls.

METHOD

Seventy-five female patients with purging BN and 30 healthy controls were compared for psychopathology (impulsivity, borderline personality traits, depressive symptoms and self-defeating personality traits) and neurobiological parameters reflecting hypothalamic-pituitary-adrenal axis activity (morning serum cortisol before and after dexamethasone) and monoamine activity (24-hour urinary excretion of norepinephrine, serotonin, dopamine, and their main metabolites: 3-methoxy-4-hydroxyphenylglycol, 5-hydroxyindoleacetic acid, and homovanillic acid). Furthermore, the relationships between the 2 sets of variables were compared in the 2 samples.

RESULTS

BN patients displayed higher impulsivity, more severe depressive features, and more borderline and self-defeating personality traits than controls. The 4 psychopathological variables were strongly interrelated in patients, whereas only depressive features correlated with self-defeating personality traits in controls. Patients had lower 24-hour excretion of serotonin and dopamine than controls, as well as lower ability to suppress cortisol. The relations between the biochemical and the psychopathological variables were only significant in the BN patients, but not in the control group. When discriminant analysis methods were applied, patients and controls differed for psychopathology (impulsive behaviors and borderline personality traits) and biological parameters (baseline cortisol and dopamine excretion), but when the variables were analyzed together, the differences in neurobiological parameters appeared as mediated by the psychopathological status.

DISCUSSION

Our results suggest that hypothalamic-pituitary-adrenal axis activity, dopamine activity and other biological parameters are worthy of further study as potential dimensional markers of BN, although they seem to depend on the psychopathological status of the patients, in such a way that the psychopathological items associated with emotional instability (impulsivity and borderline personality traits) seem to be more reliable as clinical markers at the time being.

Endocrine manifestations of eating disorders

CONTEXT

The endocrinopathies associated with eating disorders involve multiple systems and mechanisms designed to preserve energy and protect essential organs. Those systems that are most affected are in need of significant energy, such as the reproductive and skeletal systems. The changes in neuropeptides and in the hypothalamic axis that mediate these changes also receive input from neuroendocrine signals sensitive to satiety and food intake and in turn may be poised to provide significant energy conservation. These adaptive changes are described, including the thyroid, GH, and cortisol axes, as well as the gastrointestinal tract.

EVIDENCE ACQUISITION

Articles were found via PubMed search for both original articles and reviews summarizing current understanding of the endocrine changes of eating disorders based on peer review publications on the topic between 1974 and 2009.

CONCLUSION

The signals that control weight and food intake are complex and probably involve multiple pathways that appear to have as a central control the hypothalamus, in particular the medial central area. The hypothalamic dysfunction of eating disorders provides a reversible experiment of nature that gives insight into understanding the role of various neuropeptides signaling nutritional status, feeding behavior, skeletal repair, and reproductive function.

An animal model of eating disorders associated with stressful experience in early life

Experience of childhood abuse is prevalent among patients with eating disorders, and dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis is implicated in its pathophysiology. Neonatal maternal separation is considered as an animal model of stressful experience early in life. Many of studies have demonstrated its impact both on the activity of HPA axis and the development of psycho-emotional disorders later in life. In this paper, a series of our researches on developing an animal model of eating disorders is reviewed. An animal model of neonatal maternal separation was used; Sprague-Dawley pups were separated from dam daily for 180 min during the first 2 weeks of life (MS) or undisturbed. Anxiety-/depression-like behaviors were observed in MS rats at the age of two months with decreased serotonergic activity in the hippocampus and the raphe. Post-weaning social isolation promoted food intake and weight gain of adolescent MS pups, with impacts on anxiety-like behaviors. Sustained hyperphagia was observed in the MS pups subjected to a fasting/refeeding cycle repeatedly during adolescence, with increased plasma corticosterone levels. Anhedonia, major symptom of depression, to palatable food was observed in adolescent MS pups with blunted response of the mesolimbic dopaminergic activity to stress. Results suggest that neonatal maternal separation lead to the development of eating disorders when it is challenged with social or metabolic stressors later in life, in which dysfunctions in the HPA axis and the brain monoaminergic systems may play important roles.

Anorexia, bulimia, and the female athlete triad: evaluation and management

The female athlete triad is an increasingly prevalent condition involving disordered eating, amenorrhea, and osteoporosis. An athlete can suffer from all 3 components of the triad, or just 1 or 2 of the individual conditions. The main element underlying all the aspects of the triad is an adaptation to a negative caloric balance. Screening for these disorders should be an important component of an athlete's care. Prevention and treatment should involve a team approach, including a physician, a nutritionist, and a mental health provider.

Stress and obesity: the role of the hypothalamic-pituitary-adrenal axis in metabolic disease

PURPOSE OF REVIEW

Chronic stress, combined with positive energy balance, may be a contributor to the increased risk for obesity, especially upper body obesity, and other metabolic diseases. This association may be mediated by alterations in the hypothalamic-pituitary-adrenal (HPA) axis. In this review, we summarize the major research that has been conducted on the role of the HPA axis in obesity and metabolic disease.

RECENT FINDINGS

Dysregulation in the HPA axis has been associated with upper body obesity, but data are inconsistent, possibly due to methodological differences across studies. In addition to systemic effects, changes in local cortisol metabolism in adipose tissue may also influence the risk for obesity. HPA axis dysregulation may be the causal link between conditions such as maternal malnutrition and sleep deprivation with metabolic disease.

SUMMARY

The present review provides evidence for the relationship between chronic stress, alterations in HPA activity, and obesity. Understanding these associations and its interactions with other factors will be important in developing effective treatments for obesity and related metabolic diseases.

Changes of body composition in bulimia nervosa: increased visceral fat and adrenal gland size

OBJECTIVE

To study the hypothesis that young women suffering from active bulimia nervosa (BN) have more visceral fat and increased adrenal gland volumes (AGV) than healthy controls (HC).

METHODS

Thirteen patients with BN of purging type and 11 healthy age and weight matched women (HC), aged between 19 and 36 years (mean 24 +/- 3 years), with a BMI of 19 to 29 (mean 24 +/- SD 3) were examined. BN was diagnosed by DSM-IV criteria and the severity of illness by the Eating Disorder Inventory (EDI-2). Whole body fat distribution and AGV were determined using a whole body magnetic resonance (MR) scan (T1w) and a 3D-sequence (T1w) at 1.5 Tesla. Salivary cortisol was determined at 9 AM and 4 PM.

RESULTS

BN patients had significantly more visceral adipose tissue (VAT) (HC, 1589.3 +/- 967.6 ml versus 927.2 +/- 428.4 ml, p < .05) and an increased relative AGV (0.068% of body volume versus 0.048% of body volume, p < .05) compared with HC, although waist circumference and BMI did not differ. Although the VAT part in the upper abdomen was increased, especially the VAT of lower abdomen along with the pelvis or any subcutaneous fat compartment was not increased.

CONCLUSIONS

The increase of the VAT volume and the increased AGV in BN women with purging point to chronic high stress levels associated with a hyperactivity of the hypothalamic-pituitary-adrenal axis in these patients. This is the first MR study showing morphological changes in stress associated endocrine organs of young BN patients.

Hostility and helper T-cells in patients with bulimia nervosa

OBJECTIVE

The study aimed to analyze the correlation between lymphocyte counts and several psychopathological variables associated with psychological instability (depression, hostility, impulsivity, self-defeating personality traits, and borderline personality symptoms) in patients with bulimia nervosa (BN).

METHOD

Sixty BN patients were assessed, using specific scales for eating pathology, general psychopathology, impulsivity, depression, and borderline personality features. Lymphocyte and lymphocyte subset counts were performed. Plasma cortisol at 8:00, before and after administration of 1 mg of dexamethasone at 23:00, was determined. The influence of body weight, and the use of tobacco, alcohol, and caffeine was controlled. The relationship between each isolated variable and the number of immune cells was analyzed. In a second step, supplementary post-hoc analysis of the variables was introduced to confirm the accuracy of the psychopathological assessment.

RESULTS

Hostility was negatively correlated with the number of helper T-cells (CD4+). Patients with high hostility had lower CD4+ cell counts and lower CD4+/CD8+ ratios. In the post-hoc control study, hostility was significantly related with other "interpersonal" items.

CONCLUSIONS

These results support the idea that hostility, as an expression of disturbed interpersonal relationships, could play a role as a modulator of immune activity in patients with BN.