Atypical endogenous opioid systems in mice in relation to an auto-addiction opioid model of anorexia nervosa

We have proposed that the atypical opioid system in the mouse may be representative of that in the anorexia nervosa patient and may account for a biological predisposition to the disorder. This is in the context of our auto-addiction model of anorexia nervosa in which endogenous opioids play a critical role in its etiology. Morphine activation of the endogenous opioid systems increases food intake and causes sedation in most species, including normal humans and rats. In contrast in BALB/C mice, morphine causes anorexia and hyperactivity, which we suggest may be true in the anorexia nervosa patient. A variety of atypical opioid systems have been demonstrated in different mouse strains, based on other responses. The present study examines these strains with reference to the responses relevant to our anorexia nervosa model. Three patterns are described--anorexia with hyperactivity (BALB/C and C57BL/6J mice), anorexia without hyperactivity (DBA/J mice), and a biphasic curve with hyperphagia at low doses and anorexia and hyperactivity at higher doses (CF-1 mice). Only female mice were used. These atypical opioid systems may reflect a spectrum of biological predispositions to the disorder. These strain differences may also provide useful correlations of the genetic determinants of various opiate responses and provide useful comparisons in characterizing the essential features responsible for the atypical responses.     

Human pancreatic polypeptide responsiveness to insulin-induced hypoglycemia in anorexia nervosa

Patients with anorexia nervosa occasionally suffer from hypoglycemic comas. We investigated the role of human pancreatic polypeptide (HPP) in insulin-induced hypoglycemia (0.1 U/kg of regular insulin). Ten female patients with anorexia nervosa (20.7 +/- 2.0 years, mean +/- SEM; 34.9 +/- 1.7 kg, mean +/- SEM) and 8 age-matched female controls (20.9 +/- 0.6 years, 51.5 +/- 0.8 kg) were tested. In the patients with anorexia nervosa, testing was performed before and after the restoration of body weight (45.0 +/- 0.8 kg). There was no significant difference in glucose nadir between patients with anorexia nervosa and the control subjects. However, glucose recovery from nadir was delayed in patients with anorexia nervosa. In anorexia nervosa patients, the plasma pancreatic glucagon responses to insulin-induced hypoglycemia did not differ from those of the controls. Results also showed, however, that HPP responses to insulin-induced hypoglycemia were significantly higher in patients with anorexia nervosa than in controls (p less than 0.01). The increased HPP responses were still present after the restoration of body weight in anorexia nervosa patients. A complete body weight recovery or a longer period of time may be required to normalize the HPP response to insulin-induced hypoglycemia in patients with anorexia nervosa, after the restoration of body weight.     

Steroids and neuroendocrine function in anorexia nervosa

Anorexia nervosa is a primarily psychiatric syndrome of self-induced weight loss due to an intense fear of becoming obese. Numerous endocrine abnormalities occur in anorexia nervosa patients, and in many respects these alterations reflects the endocrinology of reduced energy intake. However, the basic mechanisms of those alterations are far from being understood. In an attempt to understand the disrupted mechanisms of the hypogonadotropic hypogonadism of the anorectic state, we studied 10 anorectic women in the acute phase of their illness; all met the DSM III criteria. On each patient, two tests were performed with either saline as control or infusion of the opioid antagonist naloxone, and both LH and FSH levels were measured. Four mg of naloxone as bolus was used, followed by a naloxone infusion of 2 mg/h for 4 h. Compared with the pattern of normal women, naloxone did not increase in the anorectic patients either LH or FSH levels nor pulsatility. This result suggests that endogenous opioid peptides are not implicated in the low gonadotropic situation of anorexia nervosa. An alternative explanation could be that the low estrogenic "milieu" of these patients could mask the opioid action. To test this second possibility, another group of 7 anorectic women after partial weight recovery were challenged with estrogen administration. Compared with the pattern of normal women volunteers, all the anorectic patients but one presented an abnormal response in both LH and FSH levels after estrogen administration. In fact, the negative feedback and the delayed positive feedback of LH after estrogen were absent in these patients. Interestingly enough, the only patient with near-normal LH response to estrogen was considered fully recovered by the Psychiatric Unit. Several alterations in the hypothalamic-pituitary-adrenal axis has been reported in anorexia nervosa. Seven anorectic patients and 7 aged-matched women were challenged by ACTH 1-24, 250 micrograms (i.v.) and the ratio of increments in adrenal steroid products to precursors monitored. ACTH-induced increments in cortisol with respect to increments in 17-OH-progesterone was similar in anorectics and controls. On the contrary, the ratio of increments of androstenedione with respect to increments in 17-OH-progesterone were greater in anorexia nervosa than controls. These results suggest that in anorexia nervosa the 11-beta-21-alpha-hydroxylase system is normal but a deficient 17-20 desmolase system is present. Finally, the altered pattern of GH secretion in anorexia was studied using GHRH (1 microgram/kg) as stimulus of pituitary GH secretion.(ABSTRACT TRUNCATED AT 400 WORDS)     

Resting tachycardia, a warning sign in anorexia nervosa: case report

Background

Among psychiatric disorders, anorexia nervosa has the highest mortality rate. During an exacerbation of this illness, patients frequently present with nonspecific symptoms. Upon hospitalization, anorexia nervosa patients are often markedly bradycardic, which may be an adaptive response to progressive weight loss and negative energy balance. When anorexia nervosa patients manifest tachycardia, even heart rates in the 80–90 bpm range, a supervening acute illness should be suspected.

Case presentation

A 52-year old woman with longstanding anorexia nervosa was hospitalized due to progressive leg pain, weakness, and fatigue accompanied by marked weight loss. On physical examination she was cachectic but in no apparent distress. She had fine lanugo-type hair over her face and arms with an erythematous rash noted on her palms and left lower extremity. Her blood pressure was 96/50 mm Hg and resting heart rate was 106 bpm though she appeared euvolemic. Laboratory tests revealed anemia, mild leukocytosis, and hypoalbuminemia. She was initially treated with enteral feedings for an exacerbation of anorexia nervosa, but increasing leukocytosis without fever and worsening left leg pain prompted the diagnosis of an indolent left lower extremity cellulitis. With antibiotic therapy her heart rate decreased to 45 bpm despite minimal restoration of body weight.

Conclusions

Bradycardia is a characteristic feature of anorexia nervosa particularly with significant weight loss. When anorexia nervosa patients present with nonspecific symptoms, resting tachycardia should prompt a search for potentially life-threatening conditions.     

Atypical responses to morphine in mice: a possible relationship to anorexia nervosa?

According to our previously proposed auto-addiction hypothesis of chronic anorexia nervosa, patients become addicted to an initial period of dieting through endogenous opioid mediated mechanisms. Morphine causes hyperactivity and anorexia in the mouse, symptoms of anorexia nervosa but responses opposite to those of most species including rats and normal human subjects. This suggests that the atypical opioid systems in the mouse may resemble those of the chronic anorexia nervosa patient in contrast to those of most species including the normal human. Characterization of this atypical opioid system may be useful in understanding the pathophysiology of anorexia nervosa.     

Anorexia nervosa,amenorrhea, and adaptation

Female mammals under stress or in poor physical condition often delay puberty or otherwise suppress reproduction. This capacity is adaptive because it enables females to avoid reproduction when environmental conditions are not conducive to the survival of offspring. Because amenorrhea is one of the key diagnostic criteria for this condition, anorexia nervosa is discussed in an evolutionary context. It is suggested that anorexia nervosa may delay puberty in girls who are disposed to early maturity. Since there is some evidence that early and late maturers have different life histories in modern societies, the reproductive delay associated with anorexia nervosa exhibits features compatible with an evolved reproductive strategy. Insofar as anorexia nervosa is a modern phenomenon, it is unlikely that the syndrome per se is the result of selection. Rather, anorexia nervosa appears to be a reflection of the female ability to alter maturation rates and reproductive function in response to environmental conditions.     

Association of CNR1 and FAAH endocannabinoid gene polymorphisms with anorexia nervosa and bulimia nervosa: evidence for synergistic effects

Endocannabinoids modulate eating behavior; hence, endocannabinoid genes may contribute to the biological vulnerability to eating disorders. The rs1049353 (1359 G/A) single nucleotide polymorphism (SNP) of the gene coding the endocannabinoid CB1 receptor ( CNR1 ) and the rs324420 (cDNA 385C to A) SNP of the gene coding fatty acid amide hydrolase (FAAH), the major degrading enzyme of endocannabinoids, have been suggested to have functional effects on mature proteins. Therefore, we explored the possibility that those SNPs were associated to anorexia nervosa and/or bulimia nervosa. The distributions of the CNR1 1359 G/A SNP and of the FAAH cDNA 385C to A SNP were investigated in 134 patients with anorexia nervosa, 180 patients with bulimia nervosa and 148 normal weight healthy controls. Additive effects of the two SNPs in the genetic susceptibility to anorexia nervosa and bulimia nervosa were also tested. As compared to healthy controls, anorexic and bulimic patients showed significantly higher frequencies of the AG genotype and the A allele of the CNR1 1359 G/A SNP. Similarly, the AC genotype and the A allele of the FAAH cDNA 385C to A SNP were significantly more frequent in anorexic and bulimic individuals. A synergistic effect of the two SNPs was evident in anorexia nervosa but not in bulimia nervosa. Present findings show for the first time that the CNR1 1359 G/A SNP and the FAAH cDNA 385C to A SNP are significantly associated to anorexia nervosa and bulimia nervosa, and demonstrate a synergistic effect of the two SNPs in anorexia nervosa.     

Involvement of corticotropin-releasing factor in restraint stress-induced anorexia and reversion of the anorexia by somatostatin in the rat

The mechanism by which restraint stress induces suppression of food intake and the influence of intracerebroventricular (icv) administration of somatostatin on the anorexia induced by restraint stress were examined in the rat. Ninety minutes of restraint stress reduced food intake of rats to approximately 60% that of control. Anorexia induced by 90 min restraint stress was partially reversed by icv administration of alpha-helical CRF (9-41), a corticotropin-releasing factor (CRF) antagonist, and completely reversed by anti-CRF gamma-globulin. These results provide further evidence in support of the theory that CRF is involved in the inhibitory mechanism of food intake in restraint stress. ICV administration of somatostatin 14 and SMS 201-995, an analog of somatostatin, also reversed restraint stress-induced anorexia. It is, therefore, suggested that somatostatin may counteract the suppressive action of CRF on food intake in stress.     

A child with anorexia nervosa presenting with severe infection with cytopenia and hemophagocytosis: a case report

Background

Patients with anorexia nervosa in the acute phase have physical complications, such as infectious disease. Although hemophagocytic syndrome due to infection is a rare complication in anorexia nervosa, early identification for hemophagocytosis is important for avoiding a life-threatening condition.

Case presentation

We report a case of a 12-year-old girl with anorexia nervosa presenting with infection with cytopenia and hemophagocytosis during initial nutritional therapy. She developed pyrexia, abdominal pain, and diarrhea during inpatient treatment. Although intravenous antibiotics were administered, the symptoms persisted. Acinetobacter baumannii was detected in blood culture. Hemophagocytosis was present in the bone marrow. Gamma globulin therapy was effective, with improvement in symptoms and cytopenia.

Conclusions

Although our case did not fulfill the criteria of hemophagocytic syndrome, clinicians should consider severe infection in anorexia nervosa with cytopenia and hemophagocytosis.

     

Hypothalamic pituitary adrenal function in patients with anorexia nervosa.

Hypothalamic pituitary adrenal function was studied in 14 patients with anorexia nervosa. Although basal plasma cortisol levels in the morning were elevated in most cases, basal plasma ACTH levels were not suppressed. Oral administration of 1 mg dexamethasone 10 hr before blood sampling failed to suppress plasma ACTH and cortisol levels in most patients with anorexia nervosa. Apparent biological half-life of exogenous cortisol was prolonged in all 4 patients with anorexia nervosa tested. The cortisol response to insulin-induced hypoglycemia and exogenous ACTH appeared to be blunted in these patients. It is concluded that anorexia nervosa has dysfunctions of hypothalamic pituitary adrenal axis, especially an abnormal feedback mechanism on ACTH secretion.     

Preadipocyte factor-1 concentrations in patients with anorexia nervosa: the influence of partial realimentation

Preadipocyte factor-1 (Pref-1) is a member of epidermal growth-factor like family of proteins that regulates adipocyte and osteoblast differentiation. Experimental studies suggest that circulating Pref-1 levels may be also involved in the regulation of lipid and glucose metabolism and energy homeostasis. We hypothesized that alterations in Pref-1 levels may contribute to the ethiopathogenesis of anorexia nervosa or its underlying metabolic abnormalities. We measured Pref-1 concentrations and other hormonal, biochemical and anthropometric parameters in eighteen patients with anorexia nervosa and sixteen healthy women and studied the influence of partial realimentation of anorexia nervosa patients on these parameters. The mean duration of realimentation period was 46±2 days. At baseline, anorexia nervosa patients had significantly decreased body mass index, body weight, body fat content, fasting glucose, serum insulin, TSH, free T4, leptin and total protein. Partial realimentation improved these parameters. Baseline serum Pref-1 levels did not significantly differ between anorexia nervosa and control group (0.26±0.02 vs. 0.32±0.05 ng/ml, p=0.295) but partial realimentation significantly increased circulating Pref-1 levels (0.35±0.04 vs. 0.26±0.02 ng/ml, p<0.05). Post-realimentation Pref-1 levels significantly positively correlated with the change of body mass index after realimentation (r=0.49, p<0.05). We conclude that alterations in Pref-1 are not involved in the ethiopathogenesis of anorexia nervosa but its changes after partial realimentation could be involved in the regulation of adipose tissue expansion after realimentation.     

Evolutionary biology and psychiatry: The case of anorexia nervosa

A review of the literature and an analysis of 19 case histories suggest that evolutionary mechanisms such as reproductive suppression, kin selection, and parental manipulation are involved in the development of anorexia nervosa. From this perspective, anorexia nervosa is viewed as—in some cases—an adaptive feature of human reproductive strategies and may be best understood as an emergency strategy that is pursued whenever the sovereign handling of one's own reproductive potential is not possible because of socioecological or ontogenetic constraints.     

Assessment of the relationship between serum thyroid hormone levels and peripheral metabolism in patients with anorexia nervosa

It has been observed that basal and/or TRH-stimulated serum TSH levels occasionally conflict with the actual values of circulating thyroid hormones in patients with anorexia nervosa. In the present study sixteen female patients with anorexia nervosa during self-induced starvation displayed clinical findings suggesting hypothyroidism, e.g., cold intolerance, constipation, bradycardia, hypothermia and hypercholesterolemia in association with decreased serum total T3 (62.8 +/- 5.2 ng/dl) and T4 (6.6 +/- 0.3 micrograms/dl). Markedly decreased T3 correlated positively with average heart rate (r = 0.5655, P less than 0.025) and negatively with total cholesterol (r = -0.7413, P less than 0.005). This result may suggest that peripheral metabolic state of the underweight anorexics depends considerably upon the serum T3 concentration. Despite decreased total thyroid hormones, free T4 assayed by radioimmunoassay was normal in all five cases examined (1.4 +/- 0.2 ng/dl) and the free T4 index in fifteen cases was normal except in one case. Basal TSH was not increased and TSH response to exogenous TRH was not exaggerated in any. These results may be compatible with a theory that free T4 has a dominant influence on pituitary TSH secretion. Furthermore, glucocorticoids may also have some influence on depressed TSH response, because an inverse correlation between increased plasma cortisol and the sum of net TSH increase after TRH was observed in twelve cases examined. In conclusion, it is suggested that normal sensitivity of peripheral tissues and pituitary thyrotroph to different circulating thyroid hormones is maintained in anorexia nervosa patients even during severe self-induced starvation, and that the metabolic state in these patients is considerably under the influence of circulating T3.     

Angiotensin-converting enzyme and anorexia nervosa

Angiotensin-converting enzyme (ACE) activity was measured in 10 patients with anorexia nervosa, 6 with hyperthyroid Graves' disease, and 7 with primary hypothyroidism. Patients with anorexia nervosa had a low serum ACE activity (9.8 +/- 2.2 IU/l), as compared to findings in normal subjects (13.4 +/- 3.5 IU/l) (P less than 0.05). Patients with hyperthyroid Graves' disease had high serum ACE activity (23.7 +/- 5.8 IU/l), as compared to levels in normal subjects (P less than 0.01), and patients with primary hypothyroidism tended to have low serum ACE activity (10.1 +/- 1.8 IU/l), compared to the normal subjects (P less than 0.1). Following weight gain (before; 71.3 +/- 10.2% of ideal body weight, after; 88.7 +/- 5.6% of ideal body weight), serum ACE activity in patients with anorexia nervosa reverted to within the normal range (13.8 +/- 3.5 IU/l), and serum T3 concentration was restored to the normal range (before; 0.7 +/- 0.2 ng/ml, after; 1.1 +/- 0.3 ng/ml). In these patients, ACE activity correlated with the per cent of ideal body weight (P less than 0.05). These data suggest that, in underweight subjects with anorexia nervosa, decreased serum ACE activities may relate to emaciation.     

Adipocytokines in anorexia nervosa: a review focusing on leptin and adiponectin.

Adipose tissue secretes a large number of physiologically active peptides that often share structural properties with cytokines, and are therefore collectively referred to as "adipocytokines". Some of these are almost exclusively secreted by adipose tissue. Leptin, adiponectin and resistin are specific fat-derived hormones that affect fuel homeostasis and insulin action, and may also be involved in hematopoiesis and immune functions. Anorexia nervosa is characterized by chronic self-starvation and severe weight loss, mainly at the expense of adipose tissue. Starvation-induced depletion of fat stores is accompanied by alterations of circulating adipocytokines. Plasma leptin and likely resistin levels are decreased in anorectic patients, while plasma adiponectin levels are increased. These alterations may have potential repercussions in the pathophysiology of anorexia nervosa. Thus, low leptin and high adiponectin may separately or in concert contribute to altered hematopoiesis and immunity, enhanced insulin sensitivity, neuroendocrine disturbances or osteopenia in anorexia nervosa.     

Serum leptin levels in patients with anorexia nervosa before and after partial refeeding, relationships to serum lipids and biochemical nutritional parameters.

Leptin is a protein hormone produced by adipocytes that provide information about the body fat content. It was previously reported that serum leptin levels were decreased in patients with anorexia nervosa in comparison with healthy control subjects. The aim of our study was to compare serum leptin levels in patients with anorexia nervosa (n=11, initial mean BMI=15.4 kg/m2) before and after partial recovery with control age-matched subjects (n=11, mean BMI= 20.3 kg/m2) and to study the relationships of leptin levels, serum lipids and biochemical nutritional parameters. We found that serum leptin concentrations in patients with anorexia nervosa were significantly reduced in comparison with control subjects (3.61 vs 9.37 ng.ml(-1), p<0.01). Serum cholesterol, triglycerides, total protein and albumin in patients with anorexia nervosa either before or after partial recovery did not differ from the control group. After partial recovery, a significant increase in serum leptin was observed (4.83 vs 3.61 ng.ml(-1), p<0.05), but the values still remained significantly lower than in the control group (p<0.01) Leptin levels correlated positively with the body mass index in the control group and anorexia nervosa group before recovery. The correlation with BMI in the anorexia nervosa group after refeeding was not significant. No significant correlation was found between leptin concentrations and serum lipids, total protein, albumin and prealbumin, respectively. Serum leptin thus represents a sensitive parameter that reflects the nutritional status in patients with anorexia nervosa suitable for long-term follow up during refeeding therapy.     

Human atrial natriuretic polypeptide in plasma of patients with anorexia nervosa

To examine the effects of chronic dehydration and starvation on plasma levels of human atrial natriuretic polypeptide (hANP) in human subjects, the basal level and saline-induced rise of plasma hANP in 7 patients with anorexia nervosa were compared with those in age-matched healthy subjects. The unstimulated level of plasma hANP was markedly high in the patients with anorexia nervosa (patients vs. control; 55.4 +/- 9.0 pg/ml vs. 11.4 +/- 6.1 pg/ml, P less than 0.01). However, no significant increase of plasma hANP in the anorectic patients was observed in response to saline-infusion, while a 3-fold increase over the basal level of plasma hANP was noted in the saline-infused normal young subjects. These results show that hANP may be secreted to an inadequate extent, hence the release would be resistant to volume-loading. The pathophysiological meaning of such a high plasma concentrations of hANP in anorexia nervosa is the subject of ongoing studies.     

Plasma adiponectin levels in women with anorexia nervosa.

Adiponectin is a plasma protein exclusively secreted by adipose tissue, which plays a role in modulating lipid and glucose metabolism. The plasma adiponectin concentration shows an inverse correlation with the body mass index in normal and obese individuals, but it has not been investigated in subjects with an extremely low body weight and undernutrition such as anorexia nervosa patients. We investigated plasma adiponectin levels in 21 females with anorexia nervosa. Nineteen healthy females served as the lean control group. The subjects with anorexia nervosa had a significantly lower weight and showed a tendency towards higher adiponectin levels than the control group. No correlation between adiponectin and BMI was found in patients with anorexia nervosa, while a linear negative correlation was seen in lean controls. The patient who showed the lowest adiponectin level reached a life-threatening state and required intravenous feeding in hospital. In association with improved nutrition and weight gain, the adiponectin level increased gradually until the body mass index was about 16 and then decreased subsequently as would be expected in lean normal subjects. These observations suggest that adipose tissue secretes less adiponectin and the adiponectin levels do not show an inverse correlation simply with body mass index in some subjects with severe undernutrition.     

Two cases of anorexia nervosa associated with Graves' disease

In this report on two cases of anorexia nervosa associated with Graves' disease, metabolism and the relationship between the two illness are considered. Case 1 was a 25-year-old female. Anorexia was associated with a stressful life situation following marriage. One year after the onset of anorexia, her condition was diagnosed as Graves' disease. In spite of high levels of serum thyroid hormone, she did not show the clinical signs and symptoms of hyperthyroidism. The hypermetabolic state of Graves' disease seems to be suppressed by the hypometabolism of anorexia. Case 2 was a 17-year-old female whose body weight, due to anorexia, at one time had decreased from 55 kg to 35.2 kg. A rebound from anorexia to bulimia increased her body weight to 80 kg in spite of an association with the hypermetabolic state of Graves' disease. In light of the abovementioned cases, it seems that the clinical picture of Graves' disease is usually hidden by the clinical symptoms of anorexia nervosa.     

Prolonged suppression of gonadotropin secretion after weight recovery in an anorectic patient with Turner's syndrome: reduced gonadal function in anorexia nervosa is independent in part on nutrition

Two hypotheses have been postulated as to the pathogenesis of hypogonadotropinemia in anorexia nervosa; one is starvation and weight loss and the other is a psychological factor to influence gonadotropin secretion. Our patient suffered from very rare concurrence of Turner's syndrome and anorexia nervosa and a study of this experiment in nature provided important evidences concerning decreased secretion of gonadotropins in the eating disorder. The patient was diagnosed as Turner's syndrome when she was 6 years old. Her gonadotropin levels were elevated to the castrated ranges (LH 61.8 IU/l; FSH 175.8 IU/l) after 8 years of age. She was noticed to be anorectic at the age of 13 years. Serum levels of the pituitary gonadotropins were lowered (LH 2.9 IU/l; FSH 3.0 IU/l) and their responses to luteinizing hormone-releasing hormone were decreased beneath the normal prepubertal limits. After one year of the anorectic period, she recovered the weight though her gonadotropin levels remained in the very low ranges (LH 2.7 IU/l; FSH 2.5 IU/l). The results suggest that hypogonadism in anorexia nervosa is not solely caused by nutritional deficiency but rather by other factors such as psychological abnormalities.