Hypothalamic-pituitary-adrenal-cortical activity in anorexia nervosa and bulimia

Developmental activity-based anorexia alters hippocampal non-genomic stress response and induces structural instability and spatial memory impairment in female rats

OBJECTIVE

Anorexia nervosa (AN) is characterized by hyperactivation of the hypothalamic-pituitary-adrenal axis and cognitive deficits. However, little is known about the rapid non-genomic stress response involvement. This study investigates the molecular, structural and behavioral signatures of the anorexic phenotype induction in female rats on stress-related mechanisms in the hippocampus.

METHOD

Female adolescent rats, exposed to the combination of food restriction and wheel access, i.e., the activity-based anorexia (ABA) protocol, were sacrificed in the acute phase of the pathology (postnatal day [P]42) or following a 7-day recovery period (P49).

RESULTS

ABA rats, in addition to body weight loss and increased wheel activity, alter their pattern of activity over days, showing increased food anticipatory activity, a readout of their motivation to engage in intense physical activity. Corticosterone plasma levels were enhanced at P42 while reduced at P49 in ABA rats. In the membrane fraction of the hippocampus, we found reduced glucocorticoid receptor levels together with reduced expression of caldesmon, n-cadherin and neuroligin-1, molecular markers of cytoskeletal stability and glutamatergic homeostasis. Accordingly, structural analyses revealed reduced dendritic spine density, a reduced number of mushroom-shaped spines, together with an increased number of thin-shaped spines. These events are paralleled by impairment in spatial memory measured in the spatial order object recognition test. These effects persisted even when body weight of ABA rats was restored.

DISCUSSION

Our findings indicate that ABA induction orchestrates hippocampal maladaptive structural and functional plasticity, contributing to cognitive deficits, providing a putative mechanism that could be targeted in AN patients.

Treatment-Resistant Blunted HPA Activity, but Reversible Cardiovascular Stress Reactivity in Young Women With Eating Disorders

Previous research has provided evidence for a reduced neuroendocrine stress response in women with eating disorders (EDs). In the present study female in-patients with Anorexia and Bulimia nervosa were compared to female healthy controls (HC) before and after completing an in-patient treatment program. Salivary cortisol, alpha-amylase (sAA), heart rate response (HR), high-frequency heart rate variability (HF-HRV) and negative affective state were measured before, during and after exposure to the Trier Social Stress Test (TSST) at pre- and post-treatment. Patients with EDs (n = 13) showed significantly less ED symptoms at post-treatment. Compared to HC (n = 22), patients displayed a blunted cortisol stress response combined with overall attenuated sAA levels at pre-treatment. At post-treatment, the blunted cortisol stress response was still observable, while the differences in sAA responses disappeared. HR was attenuated at pre-treatment in patients, also indicated by a stronger HF-HRV throughout the TSST. These cardiovascular differences disappeared at post-treatment. Patients reported in general (pre- and post-treatment) more negative affect compared to HC. This study provides further evidences of a hypo-reactive hypothalamus-pituitary-adrenal axis (HPA) in patients with EDs which persists even after symptom recovery while initial low cardiovascular stress reactivity apparently can be restored by psychotherapy. Given the small sample size the findings have to be considered preliminary.

Anorexia Nervosa and the Immune System-A Narrative Review

The pathogenesis of an increasing number of chronic diseases is being attributed to effects of the immune system. However, its role in the development and maintenance of anorexia nervosa is seemingly under-appreciated. Yet, in examining the available research on the immune system and genetic studies in anorexia nervosa, one becomes increasingly suspicious of the immune system’s potential role in the pathophysiology of anorexia nervosa. Specifically, research is suggestive of increased levels of various pro-inflammatory cytokines as well as the spontaneous production of tumor necrosis factor in anorexia nervosa; genetic studies further support a dysregulated immune system in this disorder. Potential contributors to this dysregulated immune system are discussed including increased oxidative stress, chronic physiological/psychological stress, changes in the intestinal microbiota, and an abnormal bone marrow microenvironment, all of which are present in anorexia nervosa.

MECHANISMS IN ENDOCRINOLOGY: Anorexia nervosa and endocrinology: a clinical update

Anorexia nervosa is a syndrome, that is collections of symptoms, which is not defined by its etiology. The severe cases are intractable. The syndrome is associated with multiple, profound endocrine alterations which may be adaptive, reactive or etiologic. Adaptive changes potentially may be inappropriate in clinical settings such as inpatient intensive re-nutrition or in a setting with somatic comorbidity. Electrolyte levels must be closely monitored during the refeeding process, and the need for weight gain must be balanced against potentially fatal refeeding complications. An important focus of clinical research should be to identify biomarkers associated with different stages of weight loss and re-nutrition combined with psychometric data. Besides well-established peripheral endocrine actions, several hormones also are released directly to different brain areas, where they may exert behavioral and psychogenic actions that could offer therapeutic targets. We need reliable biomarkers for predicting outcome and to ensure safe re-nutrition, however, first of all we need them to explore the metabolism in anorexia nervosa to open new avenues with therapeutic targets. A breakthrough in our understanding and treatment of this whimsical disease remains. Considering this, the aim of the present review is to provide an updated overview of the many endocrine changes in a clinical perspective.

Mifepristone reduces hypothalamo-pituitary-adrenal axis activation and restores weight loss in rats subjected to dietary restriction and methylphenidate administration

This study evaluates the efficacy of mifepristone on weight restoration in rats subjected to dietary restriction and methylphenidate administration. 25 female rats aged between 9 and 12 months were divided into 2 groups: 5 controls (exposed only to dietary restriction) and 20 rats that were administered 5 mg/kg/d of methylphenidate before meal exposure, for 36 days. Among rats who responded to methylphenidate (weight loss of 15-25%) weeks after its administration, a group of 6 rats continued to receive only methylphenidate ("Met" group), and another group received 10 mg/kg/d of mifepristone in addition to methylphenidate for 18 days ("Met+Mif" group; n = 6). The mean weight of the "Met+Mif" group remained significantly lower when compared to the control group (87.63 ± 2.83% vs 96.29 ± 3.26%; p < 0.001 respectively) but was significantly higher than that of the "Met" group (87.63 ± 2.83% vs. 80.61 ± 3.52%; p < 0.001 respectively). Plasma concentrations of adiponectin and gene expression of its receptors in rats brain were significantly higher in the "Met" group as compared to the "Met+Mif" and control groups (p < 0.01). Accordingly, mifepristone reduces HPA axis activation and restores weight through adipose tissue recovering. It might be considered a promising treatment for anorexia nervosa patients in future studies.

The importance of the hypothalamo-pituitary-adrenal axis as a therapeutic target in anorexia nervosa

Anorexia nervosa (AN) is an eating disorder, mainly affecting women, with a lifetime prevalence of about 1%, that can run a chronic course. While an effective pharmacotherapy is lacking, it is hypothesized that the progesterone and type II glucocorticoid receptor antagonist mifepristone (RU486) might be useful, as it is well known that the hypothalamo-pituitary-adrenal axis (HPA) is activated in AN. Even if secondary to the eating disorder, an active HPA axis may contribute to maintaining the neuroendocrine, emotional and behavioral effects observed in AN. More specifically, it is suggested that the HPA axis interacts with limbic structures, including the insular and prefrontal cortices, to uphold the changes in interoceptive and emotional awareness seen in AN. As such, it is proposed that mifepristone (RU486) reverses these effects by acting on these limbic regions. In conclusion, the theoretical efficacy of mifepristone (RU486) in improving symptoms of AN should be tested in randomized clinical trials.

The clinical biochemistry of anorexia nervosa

In anorexia nervosa, under-nutrition and weight regulatory behaviours such as vomiting and laxative abuse can lead to a range of biochemical problems. Hypokalaemia is the most common electrolyte abnormality. Metabolic alkalosis occurs in patients who vomit or abuse diuretics and acidosis in those misusing laxatives. Hyponatraemia is often due to excessive water ingestion, but may also occur in chronic energy deprivation or diuretic misuse. Urea and creatinine are generally low and normal concentrations may mask dehydration or renal dysfunction. Abnormalities of liver enzymes are predominantly characterized by elevation of aminotransferases, which may occur before or during refeeding. The serum albumin is usually normal, even in severely malnourished patients. Amenorrhoea is due to hypogonadotrophic hypogonadism. Reduced concentrations of free T4 and free T3 are frequently reported and T4 is preferentially converted to reverse T3. Cortisol is elevated but the response to adrenocorticotrophic hormone is normal. Hypoglycaemia is common. Hypercholesterolaemia is a common finding but its significance for cardiovascular risk is uncertain. A number of micronutrient deficiencies can occur. Other abnormalities include hyperamylasaemia, hypercarotenaemia and elevated creatine kinase. There is an increased prevalence of eating disorders in type 1 diabetes and the intentional omission of insulin is associated with impaired metabolic control. Refeeding may produce electrolyte abnormalities, hyper- and hypoglycaemia, acute thiamin depletion and fluid balance disturbance; careful biochemical monitoring and thiamin replacement are therefore essential during refeeding. Future research should address the management of electrolyte problems, the role of leptin and micronutrients, and the possible use of biochemical markers in risk stratification.

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.

The endocrinopathies of anorexia nervosa

OBJECTIVE

To describe the hormonal adaptations and alterations in anorexia nervosa.

METHODS

We performed a PubMed search of the English-language literature related to the pathophysiology of the endocrine disorders observed in anorexia nervosa, and we describe a case to illustrate these findings.

RESULTS

Anorexia nervosa is a devastating disease with a variety of endocrine manifestations. The effects of starvation are extensive and negatively affect the pituitary gland, thyroid gland, adrenal glands, gonads, and bones. Appetite is modulated by the neuroendocrine system, and characteristic patterns of leptin and ghrelin concentrations have been observed in anorexia nervosa. A thorough understanding of refeeding syndrome is imperative to nutrition rehabilitation in these patients to avoid devastating consequences. Although most endocrinopathies associated with anorexia nervosa reverse with recovery, short stature, osteoporosis, and infertility may be long-lasting complications. We describe a 20-year-old woman who presented with end-stage anorexia nervosa whose clinical course reflects the numerous complications caused by this disease.

CONCLUSIONS

The effects of severe malnutrition and subsequent refeeding are extensive in anorexia nervosa. Nutrition rehabilitation is the most appropriate treatment for these patients; however, it must be done cautiously.

Cytokine production by blood mononuclear cells from in-patients with anorexia nervosa

Although protein–energy malnutrition is a common cause of immunodeficiency, the immune function in underweight anorexia nervosa (AN) patients usually seems to be better preserved than would be expected. However, a deranged cytokine production and its consequences are currently being investigated in these patients. This study was aimed at measuring, over time, the capacity of peripheral blood mononuclear cells (PBMC) from AN in-patients to produce several cytokines involved in the regulation of immune responses. The in vitro production of interferon (IFN)-γ, interleukin (IL)-2, tumour necrosis factor (TNF)-α, IL-6 and IL-1β by phytohaemagglutinin-stimulated PBMC were assessed on forty female adolescents with AN. These measures were carried out twice, upon hospital admission and at discharge, which occurred on average after 1 month. Thirty-five control subjects were also studied. Cytokines were measured by ELISA kits. The production of TNF-α and IL-6 was lower and production of IL-1β higher in AN patients than in the control group at both time points of assessment. Refeeding for 1 month was not enough time to reverse these differences and patients still had a low body weight at discharge. IFN-γ production was lower in the patients than in control subjects only at discharge and no differences were found in IL-2 production between both groups. The results suggest that a mechanism involving modifications in the secretion pattern of proinflammatory cytokines could explain some immune function findings in underweight AN patients.

Mirtazapine inhibits salivary cortisol concentrations in anorexia nervosa

The antidepressant mirtazapine has been demonstrated to acutely inhibit cortisol concentrations in healthy subjects and depressed patients. Since both depressed and anorectic patients are characterized by hyperactivity of the hypothalamo-pituitary-adrenocortical (HPA) system, the clinical usefulness and the endocrinological effects of mirtazapine were investigated in anorexia nervosa (AN). Five female patients suffering from AN restricting subtype (DSM-IV criteria) were admitted to a closed ward and treated with mirtazapine for three weeks receiving 15 mg mirtazapine on day 0; 30 mg mirtazapine on day 1; and 45 mg mirtazapine per day from day 2 up to the end of the study (day 21). Besides weekly determination of clinical parameters (Body Mass Index [BMI], Hamilton Depression Rating Scale [21-HAMD]), salivary cortisol concentrations were measured before treatment (day - 1), at the beginning of treatment (day 0), after 1 week (day 7), and after 3 weeks (day 21) of treatment with mirtazapine. Saliva samples were collected hourly from 0800 up to 1,400 h. Repeated-measures ANOVA revealed a significant inhibition of salivary cortisol levels during 3-week treatment with mirtazapine (p<0.05) which became obvious already after the first mirtazapine administration (day 0). Moreover, a trend for an increase in BMI was seen (p=0.063), whereas no significant changes in 21-HAMD sum scores could be demonstrated. Double-blind, placebo-controlled studies are needed to clarify the question whether the observed changes in BMI are related to the mirtazapine-induced attenuation of HPA axis activity or whether they are due to monitoring of food intake and purgative behaviour on the closed ward.

Stress response and binge eating disorder

In clinical practice, obese patients report stress as a primary trigger for binge eating. However, the biological mechanism underlying this relationship is poorly understood. This paper presents, a theoretical overview of how cortisol secretion, a major component of the stress response, could play a role in binge eating, given that exogenous glucocorticoids can lead to obesity by increasing food intake. I will discuss findings from recent studies demonstrating links between laboratory stress, cortisol, food intake and abdominal fat in humans. Cortisol is elevated following laboratory stressors in women with anorexia nervosa (AN), bulimia nervosa (BN), and obesity, but has not been widely studied in women with binge eating disorder (BED). Additionally, I will review recent findings demonstrating a greater cortisol response to stress in obese women with BED compared to non-BED.

New targets in the treatment of anorexia nervosa

The pathophysiology of anorexia nervosa (AN) is complex and involves alterations of serotonin, dopamine and histamine neurotransmitters. In addition, receptor activity is disturbed, presumably in response to the neurotransmitter changes. These alterations are reviewed in relation to symptomatology and outcome of AN. Neuropeptide and peripheral orexigenic and satiety peptide research is in its infancy but holds much promise to shed light on the pathophysiological mechanisms involved in this illness. Current drug therapies have not demonstrated the efficacy desired in the treatment of AN. Current therapies are reviewed and new drug targets are explored. Compounds that interact with serotonin, histamine and dopamine receptors may offer unique treatment opportunities. In the future, the manipulation of peptides may add to the therapeutic potential of pharmacotherapy.

Pregnancy and neonatal outcomes in women with eating disorders

OBJECTIVE

This study was initiated to examine pregnancy and neonatal outcomes in women with past or current eating disorders as compared with a control group.

METHODS

Forty-nine nulliparous nonsmoking women previously diagnosed with eating disorders (24 anorexia nervosa, 20 bulimia nervosa, 5 eating disorders not otherwise specified) and 68 controls were recruited in early pregnancy. Data on antenatal complications, mode of delivery, and neonatal outcome variables were collected. For comparisons between groups 1-way analysis of variance or chi(2) test was used.

RESULTS

Twenty-two percent of the patients had a verified relapse in eating disorders during pregnancy. Women with past or current eating disorders were at increased risk of hyperemesis (P < .01) and delivered infants with significantly lower birth weight (P < .01) and smaller head circumference (P < .001) as compared with controls. They were also at greater risk of delivering infants with microcephaly (P < .05) and small for gestational age infants (P < .05).

CONCLUSION

Pregnant women with past or active eating disorders seem to be at greater risk for delivering infants with lower birth weight, smaller head circumference, microcephaly, and small for gestational age.

LEVEL OF EVIDENCE

II-2.

Cortisol, hunger, and desire to binge eat following a cold stress test in obese women with binge eating disorder

OBJECTIVE

Increased basal cortisol levels have been found in bulimia nervosa. After stress, increased cortisol levels have been associated with increased food intake in healthy women. Therefore, we assessed cortisol, hunger, and desire to binge eat after a cold pressor test (CPT) among women with binge eating disorder (BED).

METHODS

Twenty-two obese (body mass index [BMI] = 36.7 +/- 6.5 SD) females (11 non-BED, 11 BED) completed the Zung depression scale and underwent the CPT, hand submerged in ice water for 2 minutes. Over 60 minutes, periodic ratings of hunger and desire to binge eat were obtained, just before blood draws for cortisol, as well as insulin. On a separate day, participants had a 1-mg oral dexamethasone suppression test (DST).

RESULTS

The BED group had higher depression scores than the non-BED (p = .04), but depression was not a significant covariate for the cortisol response or to DST. After controlling for contraceptive use (n = 3), the BED group had higher basal cortisol than the non-BED group (p = .03), but cortisol did not differ after DST (p = .40). The BED group had nearly significant greater cortisol AUC after the CPT (p = .057) after controlling for insulin AUC and contraceptive use (p = .057). The BED group also had greater AUC for hunger (p = .03) and desire to binge eat (p = .02) after the CPT.

CONCLUSION

These findings support our hypothesis of a hyperactive HPA-axis in BED, which may contribute to greater hunger and binge eating.

The psychopharmacotherapy of anorexia nervosa: clinical, neuroendocrine and metabolic aspects

Anorexia nervosa (AN) is a complex mental disorder presenting psychiatric and physical symptoms. Literature recognizes the role of several factors in the pathogenesis of this disorder, according to the biopsychosocial model. Many mechanisms are still partly unclear. Endocrine and metabolic alterations usually occur in AN, probably having a role in its pathogenesis and in the disorder perseverance. In consideration of the multifactorial pathogenesis, a multidisciplinary approach is needed in the treatment of anorexic patients. Up-to-date psychotherapy, psychopharmacological, endocrine and nutritional treatments are considered effective in improving AN. Literature does not however provide evidence of a single validated psychopharmacotherapy for anorexic patients. It is known that psychopharmacotherapy can influence hormonal and metabolic states in some conditions, but for the moment few data are present about these effects in AN. This article aims to review the data about the psychopharmacotherapy role in AN, focusing on the endocrine and metabolic effects of anti-depressants (AD) and novel antipsychotic drugs which seem to be the most effective in AN. Scant data are however available and further research should provide more evidence about these effects and also assess whether the severity of the neuroendocrine, hormonal and metabolic impairments can predict the lack of response to the psychopharmacological treatment with AD and neuroleptics.

Update on endocrine disturbances in anorexia nervosa

The marked endocrine changes that occur in anorexia nervosa have aroused a great deal of interest, and over the last decade much research has been conducted in this field. The endocrine disturbances are not specific to this disorder, as they also occur in starvation states secondary to other causes, and they return to normal upon weight restoration. However, emaciation may have profound effects on psychological processes, establishing an intricate circular interaction whereby somatic and psychological manifestations of starvation may continue to act. The purpose of this paper is to provide an overview of the large body of literature concerning endocrine aspects of anorexia nervosa with the main focus on the latest results, which provide leads for potential etiological theories.

Dexamethasone suppression test using saliva cortisol measurement in bulimia nervosa

The assessment of cortisol in saliva has been proven a valid and reliable reflection of the respective unbound hormone in blood. In the present study, a standard dexamethasone suppression test (DST) with measures of salivary cortisol levels was performed in bulimic women without depression (DSM-IV; N=48) and healthy controls (N=24) matched for age. Feedback sensitivity was assessed using the standard DST with pre- and post-measures of salivary cortisol. Subjects were divided into suppressors and nonsuppressors according to their post-DST levels. Bulimic suppressors and nonsuppressors were compared for their basal cortisol levels, body weight (body mass index, BMI), previous episodes of anorexia nervosa, and their results in psychometric tests. A total of 16 (33.3%) out of 48 women with bulimia nervosa (BN) failed to suppress in the DST. Basal salivary cortisol levels were elevated in bulimic nonsuppressors. Significant differences between suppressors and nonsuppressors were found for body weight and previous episodes of anorexia nervosa. The results are in accordance with recent findings. They support the hypothesized association between low body weight and DST nonsuppression. Using saliva cortisol in the standard DST could be advantageous for studying bulimic patients. Furthermore, the results show the importance of determining HPA reagibility when measuring cortisol in bulimic patients.

Cytokine production in patients with anorexia nervosa, bulimia nervosa, and obesity

OBJECTIVE

We previously reported elevated serum levels of the cytokines interleukin-6 (IL-6) and transforming growth factor-beta (TGF-beta) in patients with anorexia nervosa (AN). We investigated the cellular production of these two cytokines and of interferon-gamma (IFN-gamma), interleukin-1alpha (IL-1alpha), and tumor necrosis factor-alpha (TNF-alpha) in subjects with AN, bulimia nervosa (BN), and obesity as well as in normal-weight control subjects.

METHODS

Supernatant fluids from isolated peripheral blood mononuclear cells (PBMC) incubated with and without concanavalin A (ConA) were assayed for cytokine concentrations by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Significant differences across the four groups were found in the stimulated cellular production of IFN-gamma and IL-6. Stimulated IFN-gamma production was elevated in the AN group compared to controls. IL-6 production was significantly elevated in obese subjects relative to the two normal-weight groups, BN and controls, and tended to be higher in the AN group than in the controls, but not significantly so. IL-1alpha production was greater in obese subjects.

CONCLUSION

The findings of increased IFN-gamma production and a tendency toward increased IL-6 production (both of which suppress food intake in animals) in individuals who severely restrict food intake suggest a potential role for these cytokines in the pathogenesis of AN. Elevated IL-6 and IL-1alpha production by PBMC in obese individuals requires further investigation to determine if these cytokines contribute to the development or perpetuation of obesity.

Homeostatic joint amplification of pulsatile and 24-hour rhythmic cortisol secretion by fasting stress in midluteal phase women: concurrent disruption of cortisol-growth hormone, cortisol-luteinizing hormone, and cortisol-leptin synchrony

Short-term fasting as a metabolic stress evokes prominent homeostatic reactions of the reproductive, corticotropic, thyrotropic, somatotropic, and leptinergic axes in men and women. Although reproductive adaptations to fasting are incompletely studied in the female, nutrient deprivation can have major neuroendocrine consequences in the follicular phase. Unexpectedly, a recent clinical study revealed relatively preserved sex steroid and gonadotropin secretion during short-term caloric restriction in the midluteal phase of the menstrual cycle. This observation suggested that female stress-adaptive responses might be muted in this sex steroid-replete milieu. To test this hypothesis, we investigated the impact of fasting on daily cortisol secretion in healthy young women during the midluteal phase of the normal menstrual cycle. Eight volunteers were each studied twice in separate and randomly ordered short-term (2.5-day) fasting and fed sessions. Pulsatile cortisol secretion, 24-h rhythmic cortisol release, and the orderliness of cortisol secretory patterns were quantified. Within-subject statistical comparisons revealed that fasting increased the mean serum cortisol concentration significantly from a baseline value of 8.0+/-0.61 to 12.8+/-0.85 microg/dL (P = 0.0003). (For Systeme International conversion to nanomoles per L, multiply micrograms per dL value by 28.) Pulsatile cortisol secretion rose commensurately, viz. from 101+/-11 to 173+/-16 microg/dL/day (P = 0.0025). Augmented 24-h cortisol production was due to amplification of cortisol secretory burst mass from 8.2+/-1.5 to 12.9+/-2.0 microg/dL (P = 0.017). In contrast, the estimated half-life of endogenous cortisol (104+/-9 min), the calculated duration of underlying cortisol secretory bursts (16+/-7 min) and their mean frequency (14+/-2/day) were not altered by short-term fasting. The quantifiable orderliness of cortisol secretory patterns was also not influenced by caloric restriction. Nutrient deprivation elevated the mean of the 24-h serum cortisol concentration rhythm from 12.4+/-1.3 to 18.4+/-1.9 microg/dL (P = 0.0005), without affecting its diurnal amplitude or timing. Correlation analysis disclosed that fasting reversed the positive relationship between cortisol and LH release evident in the fed state, and abolished the negative association between cortisol and GH as well as between cortisol and leptin observed during nutrient repletion (P < 0.001). Pattern synchrony between cortisol and GH as well as that between cortisol and LH release was also significantly disrupted by fasting stress. In summary, short-term caloric deprivation enhances daily cortisol secretion by 1.7-fold in healthy midluteal phase young women by selectively amplifying cortisol secretory burst mass and elevating the 24-h rhythmic cortisol mean. Augmentation of daily cortisol production occurs without any concomitant changes in cortisol pulse frequency or half-life or any disruption of the timing of the 24-h rhythmicity or orderliness of cortisol release. Fasting degrades the physiological coupling between cortisol and LH, cortisol and GH, and cortisol and leptin secretion otherwise evident in calorie-sufficient women. We conclude that the corticotropic axis in the young adult female is not resistant to the stress-activating effects of short-term nutrient deprivation, but, rather, evinces strong adaptive homeostasis both monohormonally (cortisol) and bihormonally (cortisol paired with GH, LH, and leptin).

The relationship between eating disorders and personality in physically active women

The aim of the study was to examine the relationship between personality factors, self-reported eating disorders, type of physical activity, level of sport competition and hours spent on physical activity each week among physically active non-athletes and athletes. A total of 591 high school women participated in the study. The mean age was 19 during the data collection. Scores were obtained on the Karolinska Scales of Personality (KSP) and a questionnaire concerning eating disorders (1) and physical activity. All diagnoses were based upon the DSM-IV criteria for anorexia nervosa (AN), bulimia nervosa (BN) and eating disorder not otherwise specified (EDNOS). The prevalence of AN was 1.5%, BN 2.0%, AN+BN 0.3% and EDNOS 12.9%. The prevalence of eating disorders (ED) was highest among physically active non-athletes who were members of fitness clubs (odds ratio (OR)= 1.86, 95% CI: 1.08-2.79). However, there was no relationship between the prevalence of eating disorders and the level of sport competition or time spent on physical activity. The results showed that women with eating disorders scored higher in anxiety, hostility and detachment, and lower in socialisation than the women without eating disorders. The results indicated that individuals with certain personality characteristics had a higher risk for being classified with ED, but it does not seem to be related to whether they are physically active or not. The findings in this study may support the hypothesis that participating in physical activity can have some positive psychological effects, but this does not necessarily apply to patients with AN and BN. ED may have a biological/genetic explanation according to Eysenck's personality theory.

A review of endocrine changes in anorexia nervosa

Anorexia nervosa is a syndrome of unknown etiology. It is associated with multiple endocrine abnormalities. Hypothalamic monoamines (especially serotonin), neuropeptides (especially neuropeptide Y and cholecystokinin) and leptin are involved in the regulation of human appetite, and in several ways they are changed in anorexia nervosa. However, it remains to be clarified whether the altered appetite regulation is secondary or etiologic. Increased secretion of corticotropin-releasing hormone and proopiomelanocortin seems to be secondary to starvation, however, there is evidence that it may maintain and intensify anorexia, excessive physical activity and amenorrhea. Hypothalamic amenorrhea, which is a diagnostic criterion in anorexia nervosa, is not solely related to the low body weight and exercise. Growth hormone resistance with low production of insulin-like growth factor I and high growth hormone secretion reflect the nutritional deprivation. The nutritional therapy of patients with anorexia nervosa might be improved by administering an anabolic agent such as growth hormone or insulin-like growth factor I. So far none of the endocrine abnormalities have proved to be primary, however, there is increasing evidence that some of these might participate in a vicious circle.

Changes in bone turnover markers and menstrual function after short-term oral DHEA in young women with anorexia nervosa

Bone loss is a serious consequence of anorexia nervosa (AN). Subnormal levels of serum dehydroepiandrosterone (DHEA) are seen in patients with AN and may be causally linked to their low bone density. We hypothesized that oral DHEA would decrease markers of bone resorption (urinary N-telopeptides [NTx]), and increase markers of bone formation (serum bone-specific alkaline phosphatase and osteocalcin [OC]). Fifteen young women (age 15-22 years) with AN were enrolled in a 3-month, randomized, double-blinded trial of 50, 100, or 200 mg of daily micronized DHEA. Blood and urinary levels of adrenal and gonadal steroids and bone turnover markers were measured. No adverse clinical side effects of DHEA were noted, and a 50 mg daily dose restored physiologic hormonal levels. At 3 months, NTx levels had decreased significantly in both the 50 mg (p = 0.018) and the 200 mg (p = 0.016) subgroups. OC levels simultaneously increased within treatment groups over time (p = 0.002). Eight out of 15 (53%) subjects had at least one menstrual cycle while on therapy. Short-term DHEA was well-tolerated and appears to normalize bone turnover in young women with AN. Resumption of menses in over half of subjects suggests that DHEA therapy may also lead to estradiol levels sufficient to stimulate the endometrium in this group of patients.

The immune system in eating disorders: an overview

Eating disorders, such as anorexia nervosa and bulimia nervosa, are becoming more and more common in our society. Although they are psychiatric illnesses, there are many factors involved, including abnormal food behavior. Nutrients play an important role in the development and functionality of immunocompetent cells. An impaired immunocompetence has been shown to be an important causal factor in the increased susceptibility of malnourished individuals to infectious disease. Therefore, studies on the immune system are of great interest when assessing the extent to which the nutritional status of these patients could be affected. However, the literature in this field is controversial, and the mechanisms are not yet completely defined, although some hypotheses try to clarify the disturbances caused in the organism under these bizarre circumstances. In spite of the fact that the immune system is altered by distorted food behaviors, such as in eating disorders, the awareness of characteristics of other systems involved, and therefore altered, by these pathologies would be very helpful for understanding the mechanisms triggered in these syndromes. In fact, the interactions among the immune and other systems in eating disorders are beginning to be studied. Finally, the main goals are to limit the evolution of these illnesses through early diagnosis, and to devise a long-lasting, definitive cure for these patients through appropriate therapy.

Circadian patterns of cortisol, prolactin, and growth hormonal secretion during bingeing and vomiting in normal weight bulimic patients

Women who are of normal weight and have bulimia nervosa exhibit multiple neuroendocrine disturbances. We hypothesized that bingeing and vomiting behavior could be contributory because food consumption in healthy volunteers increases plasma cortisol and prolactin secretion and suppresses growth hormone secretion. Thus, we investigated the effects of bingeing and vomiting on the circadian pattern (measurements every 20 min for 24 hr) of these hormones in comparison to healthy control women eating normally. Bingeing and vomiting were associated with modest increases in cortisol and prolactin and reductions in growth hormone secretion. However, this bingeing or purging did not alter mean 24-hr pattern of cortisol and growth hormone secretion as values for bulimics were similar to controls. While mean daytime patterns of prolactin secretion were similar in bulimics and controls, bulimic patients had a significant reduction of nocturnal prolactin levels. In summary, bingeing and vomiting does not appear to have a substantial influence on hormonal secretion. However, bulimic women have blunted nocturnal prolactin patterns.

The dexamethasone suppression test in anorexia nervosa. The influence of weight, depression, adrenocorticotrophic hormone and dexamethasone

When 20 female anorexic in-patients were investigated with weekly DSTs, 10 had an abnormal result at initial testing. There was no identifiable relationship between severity of weight loss and DST status; % ideal body weight was no different between suppressors and non-suppressors. There was no consistent relationship between normalisation of the DST response and weight gain. Depressive symptoms were common, with half the patients scoring 20 or more on the HRSD. Plasma ACTH concentrations before and after the DST were normal. There was a significant negative correlation between plasma dexamethasone concentrations and pre- and post-dexamethasone plasma cortisol concentrations.

Disturbances in the hypothalamo-pituitary-adrenal and other neuroendocrine axes in bulimia

Disturbances in the hypothalamo-pituitary-adrenal (HPA) and other endocrine axes were assessed in 24 women with bulimia and healthy controls. Overnight blood samples for measuring nocturnal plasma cortisol, prolactin (PRL), growth hormone (GH), luteinizing hormone (LH), and follicle stimulating hormone (FSH) were obtained at 30-min intervals. A 1.5 mg dexamethasone suppression test (DST) and a TRH-test were performed. Patients were monitored closely while their nutritional intake was recorded over 21 days. Compared with healthy controls, nocturnal cortisol plasma levels were not elevated in the bulimics. There was a trend toward insufficient cortisol suppression in the DST in patients with bulimia, which was most pronounced in patients with signs of restricted caloric intake. Plasma dexamethasone levels were significantly reduced in bulimics compared with healthy controls. There was a trend for blunted thyrotropin stimulating hormone (TSH) responses to thyrotropin releasing hormone (TRH) in bulimia. The prolactin response to TRH was significantly reduced in bulimics with a history of anorexia nervosa. Plasma LH and plasma FSH were significantly reduced in bulimics with signs of reduced caloric intake [low T3, high levels of beta-hydroxy-butyric acid (BHBA), reduced daily caloric intake, high number of fasting days] as compared with healthy controls. Bulimics with high BHBA levels had significantly reduced nocturnal prolactin plasma levels. Results show that multiple neuroendocrine disturbances exist in bulimia in a milder form than in anorexia nervosa. Evidence for the impact of caloric intake on endocrine functions is presented. Endocrine dysfunctions in our bulimic sample did not show a positive association with the presence of depressive symptoms.

Luteinizing hormone and cortisol responses to naloxone in normal weight women with bulimia

The present study was undertaken in order to establish whether alterations in the endogenous opioid control of luteinizing hormone (LH) and ACTH/cortisol secretion occur in bulimic women with normal body weight and normal menstrual cycles. For this purpose, the capability of the opioid antagonist naloxone (4 mg injected as an intravenous bolus at time 0, plus 10 mg infused over 2 hr) to increase the circulating levels of LH and cortisol was tested in nine bulimic women and in nine age- and weight-matched normal controls. All women were tested on the 22nd day of a normal menstrual cycle. Two days later, a control test with normal saline (NaCl 0.9%) instead of naloxone was performed. The basal levels of LH and cortisol were similar in the bulimic and normal subjects and were not modified by the administration of normal saline. In contrast, the administration of naloxone significantly increased plasma LH and cortisol levels in all subjects, with peak LH responses at 30 min and peak cortisol responses at 60 min. The naloxone-induced LH and cortisol increases were significantly higher in the bulimic women than in the normal controls. These data indicate the presence of an increased opioid inhibitory tone in the control of LH and ACTH/cortisol secretion in normal weight bulimic women with normal menstrual cycles.

Hypothalamic-pituitary-gonadal function in anorexia nervosa and bulimia

Patients with anorexia nervosa (AN) exhibit neuroendocrine abnormalities that may result solely from emaciation or may reflect defective endocrine mechanisms which are intrinsic to disordered eating even in the absence of starvation. To distinguish these possibilities, we have studied indices of hypothalamic-pituitary-gonadal (HPG) function in 9 patients with AN, 12 normal weight patients with bulimia and recent or current oligomenorrhea, and 8 normal weight controls. Measurement of 24-hour luteinizing hormone (LH) secretion with 30-min sampling revealed significantly fewer LH secretory spikes and a trend toward lower mean 24-hour LH levels in both bulimic and anorectic patients than in controls. Stimulation with gonadotropin releasing hormone produced elevated LH responses in the bulimic group and blunted LH responses in the anorectic group. Stimulation with estradiol revealed diminished LH augmentative responses and a trend toward diminished follicle stimulating hormone augmentative responses among bulimic as well as AN patients compared to controls. In each instance, the bulimic group tended to show within-group heterogeneity, with some individuals falling within the AN range. These findings suggest that HPG axis abnormalities in eating disordered patients cannot entirely be attributed to emaciation and that factors other than subnormal weight contribute to disturbed hypothalamic-pituitary functioning in these patients.

The effect of bingeing and vomiting on hormonal secretion

Women who are of normal weight and have bulimia nervosa have multiple neuroendocrine disturbances. The reasons for these neuroendocrine abnormalities are not known, but there are reasons to suspect that bingeing and vomiting behavior could be contributory. It is well known that food consumption in healthy volunteers increases plasma insulin, cortisol, and prolactin secretion and suppresses growth hormone secretion, whereas activation of the emetic reflex increases plasma arginine vasopressin (AVP) secretion. The purpose of this study was to investigate the effects of bingeing and vomiting on these hormones. In comparison with healthy control women consuming a large meal, bulimic patients, when bingeing and vomiting, had an exaggerated secretion of either the amount and/or the duration of insulin, cortisol, and prolactin. Vasopressin secretion was not increased during or after bingeing and vomiting, probably because bulimic subjects do not become nauseated. In addition, bulimic patients had significantly reduced baseline plasma prolactin and possibly elevated baseline cortisol compared with controls. In summary, this study supports the presence of neuroendocrine disturbances in bulimia and raises a question as to whether or not excessive and prolonged food consumption (and/or vomiting) are contributory.