Brain-Derived Neurotrophic Factor and Oxytocin Signaling in Association With Clinical Symptoms in Adolescent Inpatients With Anorexia Nervosa-A Longitudinal Study

The BDNF Protein is Associated With Glucose Homeostasis and Food Intake in Carriers of Common BDNF Gene Variants

CONTEXT

Brain-derived neurotrophic factor (BDNF) concentrations may differ between BDNF genotype carriers. These changes occur in individuals with metabolic and mental disorders.

OBJECTIVE

The aim of this study was to assess the associations of glucose homeostasis parameters and the frequency of food consumption with BDNF protein concentrations based on BDNF single nucleotide polymorphisms (SNPs).

METHODS

Among the 439 participants, some common rs10835211 BDNF gene variants were analyzed. We evaluated BDNF concentrations, and measured glucose and insulin after fasting and during oral glucose tolerance tests. Anthropometric measurements, body composition, and body fat distribution were assessed, and a 3-day food intake diary and food frequency questionnaire were completed.

RESULTS

We observed significant differences in BDNF concentration between AA and AG genotype rs10835211 carriers (P = .018). The group of AA genotype holders were older, and positive correlation was found between age and BDNF in the whole study population (P = .012) and in the GG genotype carriers (P = .023). Moreover, BDNF protein correlated with fasting insulin (P = .015), HOMA-IR (P = .031), HOMA-B (P = .010), and the visceral/subcutaneous adipose tissue (VAT/SAT) ratio (P = .026) in the GG genotype individuals. Presence of the GG genotype was negatively correlated with nut and seed (P = .047) and lean pork consumption (P = .015), and the BDNF protein. Moreover, we observed correlations between the frequency of chicken (P = .028), pasta (P = .033), and sweet food intake (P = .040) with BDNF concentration in the general population. Among carriers of the AA genotype, we observed a positive correlation between the consumption of rice (P = .048) and sweet food (P = .028) and the BDNF protein level.

CONCLUSION

Peripheral BDNF may be associated with VAT content and insulin concentrations in GG genotype carriers and may vary with particular food intake, which warrants further investigation.

Assessment of brain-derived neurotrophic factor and irisin concentration in children with chronic kidney disease: a pilot study

Patients suffering from chronic kidney disease (CKD) are particularly placed at risk of multiorgan complications. One of them is malnutrition, which adds up to a higher mortality factor among them. This study was designed to determine the usefulness of brain-derived neurotrophic factor (BDNF) and irisin assays in the assessment of CKD development. The study group included 28 children with CKD at stages 2-5 treated conservatively. The outcome of our study revealed decreased serum BDNF and irisin levels in CKD patients, whereas urine concentrations were increased for BDNF and decreased for irisin, comparing to healthy controls. There was a positive correlation between anthropometric measures and urine BDNF concentration, as well as anthropometric measures and both serum and urine irisin levels in the study group, however no dependence of the tested markers on the stage of CKD was observed. In recent years, a role of myokines was described as vital for maintaining metabolic homeostasis therefore we suspect a potential role of these multifaceted markers in detecting malnutrition in CKD children.

The Role of Central and Peripheral Brain-Derived Neurotrophic Factor (BDNF) as a Biomarker of Anorexia Nervosa Reconceptualized as a Metabo-Psychiatric Disorder

Neurotrophic factors play pivotal roles in shaping brain development and function, with brain-derived neurotrophic factor (BDNF) emerging as a key regulator in various physiological processes. This review explores the intricate relationship between BDNF and anorexia nervosa (AN), a complex psychiatric disorder characterized by disordered eating behaviors and severe medical consequences. Beginning with an overview of BDNF's fundamental functions in neurodevelopment and synaptic plasticity, the review delves into recent clinical and preclinical evidence implicating BDNF in the pathophysiology of AN. Specifically, it examines the impact of BDNF polymorphisms, such as the Val66Met variant, on AN susceptibility, prognosis, and treatment response. Furthermore, the review discusses the interplay between BDNF and stress-related mood disorders, shedding light on the mechanisms underlying AN vulnerability to stress events. Additionally, it explores the involvement of BDNF in metabolic regulation, highlighting its potential implications for understanding the metabolic disturbances observed in AN. Through a comprehensive analysis of clinical data and animal studies, the review elucidates the nuanced role of BDNF in AN etiology and prognosis, emphasizing its potential as a diagnostic and prognostic biomarker. Finally, the review discusses limitations and future directions in BDNF research, underscoring the need for further investigations to elucidate the complex interplay between BDNF signaling and AN pathology.

Relationship between BDNF and oxytocin

Converging, albeit scattered data mainly gathered in animals indicate that the neurotrophin brain-derived neurotrophic factor (BDNF) and the nonapeptide oxytocin (OT) interact in a cooperative way. Data in humans are really limited and indirect. Therefore, the aim of the present study was to explore the possible existence of a link between OT and BDNF in humans, by means of two peripheral markers, the platelet-poor-plasmatic-BDNF (PPP-BDNF) and the platelet BDNF (PLT-BDNF) and OT levels. Twenty-six young healthy controls of both sexes who volunteered for the study were included in the study. Fifty ml of peripheral venous blood were drawn from one-night fasting subjects between 8.00 and 9.00 a.m. The BDNF and OT assays were carried out according to common methods. Comparisons for continuous variables were performed by the Student's t-test for variables that follow a normal distribution, and by the Wilcoxon-Mann-Whitney test for variables not normally distributed. The correlations between biological markers were explored by calculating the Pearson's correlation coefficient or Spearman's rank correlation. The results showed that PLT-BDNF (pg/mg proteins, mean ± SD) and PPP-BDNF (pg/ml, mean ± SD) were 1546 ± 1844 and 10111 ± 1892, respectively. The OT levels (pg/ml, mean ± SD) were 13.92 ± 4.54. The OT levels were significantly higher in women than in men. The Spearman's analysis revealed a statistically significant and negative correlation between OT levels and PLT-BDNF (R = -0.543, p = 0.004). The findings of this study highlight the presence of a significant and negative correlation between OT and PLT-BDNF in a small group of healthy controls of both sexes. In any case, despite all the limits of peripheral biomarkers, they suggest that this reciprocal influence might have a downstream homeostatic function dampening one activity when the other is activated or no longer necessary, maybe at the level of the stress and/or immune systems.

Similarities and differences regarding acute anorexia nervosa and semi-starvation: does behavioral thermoregulation play a central role?

Objective

To clarify the association between acute anorexia nervosa (AN) and semi-starvation (SS) by focusing on similarities and differences in physiology, mood, and behavior.

Method

A comparison of published literature between these two groups.

Results

Both groups show similar hormonal and metabolic changes in response to caloric restriction and extreme weight loss (~25%). Associated changes result in a reduced body temperature (Tcore-low). Maintenance of body temperature within a specific range is crucial to survival. However, both groups cannot activate autonomic strategies to maintain their Tcore-low, such as increasing metabolic rate, constricting skin blood vessels, or shivering. Furthermore, Tcore-low increases the individuals' "coldness sensations" throughout the body, hence the frequent reports from ANs and SSs of "feeling cold." To eliminate these uncomfortable "coldness sensations" and, importantly, to maintain Tcore-low, ANs, and SSs "select" different thermoregulatory behavioral strategies. It is proposed that the primary differences between AN and SS, based on genetics, now manifest due to the "selection" of different thermo-regulatory behaviors. AN patients (ANs) "select" hyperactive behavior (HyAc), which increases internal metabolic heat and thus assists with maintaining Tcore-low; in harmony with hyperactive behavior is a lively mood. Also related to this elevated arousal pattern, ANs experience disrupted sleep. In contrast, SS individuals "select" a passive thermo-behavioral strategy, "shallow torpor," which includes reduced activity, resulting in energy conservation. In addition, this inactivity aids in the retention of generated metabolic heat. Corresponding to this lethargic behavior, SS individuals display a listless mood and increased sleep.

Conclusion

Initial similarities between the two are attributable to physiological changes related to extreme weight loss. Differences are most likely attributable to genetically programmed "selection" of alternate thermoregulatory strategies, primarily to maintain Tcore-low. However, if acute AN is prolonged and evolves into a chronic condition, AN will more closely align with starvation and more precisely reflect SS symptomology.

The Role of Brain-Derived Neurotrophic Factor (BDNF) in Diagnosis and Treatment of Epilepsy, Depression, Schizophrenia, Anorexia Nervosa and Alzheimer's Disease as Highly Drug-Resistant Diseases: A Narrative Review

Brain-derived neurotrophic factor (BDNF) belongs to the family of neurotrophins, which are growth factors with trophic effects on neurons. BDNF is the most widely distributed neurotrophin in the central nervous system (CNS) and is highly expressed in the prefrontal cortex (PFC) and hippocampus. Its distribution outside the CNS has also been demonstrated, but most studies have focused on its effects in neuropsychiatric disorders. Despite the advances in medicine in recent decades, neurological and psychiatric diseases are still characterized by high drug resistance. This review focuses on the use of BDNF in the developmental assessment, treatment monitoring, and pharmacotherapy of selected diseases, with a particular emphasis on epilepsy, depression, anorexia, obesity, schizophrenia, and Alzheimer's disease. The limitations of using a molecule with such a wide distribution range and inconsistent method of determination are also highlighted.

Long-lasting BDNF signaling alterations in the amygdala of adolescent female rats exposed to the activity-based anorexia model

Introduction: Anorexia nervosa (AN) is a severe psychiatric disorder characterized by a pathological fear of gaining weight, excessive physical exercise, and emotional instability. Since the amygdala is a key region for emotion processing and BDNF has been shown to play a critical role in this process, we hypothesized that alteration in the amygdalar BDNF system might underline vulnerability traits typical of AN patients. Methods: To this end, adolescent female rats have been exposed to the Activity-Based Anorexia (ABA) protocol, characterized by the combination of caloric restriction and intense physical exercise. Results: The induction of the anorexic phenotype caused hyperactivity and body weight loss in ABA animals. These changes were paralleled by amygdalar hyperactivation, as measured by the up-regulation of cfos mRNA levels. In the acute phase of the pathology, we observed reduced Bdnf exon IX, exon IV, and exon VI gene expression, while mBDNF protein levels were enhanced, an increase that was, instead, uncoupled from its downstream signaling as the phosphorylation of TrkB, Akt, and S6 in ABA rats were reduced. Despite the body weight recovery observed 7 days later, the BDNF-mediated signaling was still downregulated at this time point. Discussion: Our findings indicate that the BDNF system is downregulated in the amygdala of adolescent female rats under these experimental conditions, which mimic the anorexic phenotype in humans, pointing to such dysregulation as a potential contributor to the altered emotional processing observed in AN patients. In addition, since the modulation of BDNF levels is observed in other psychiatric conditions, the persistent AN-induced changes of the BDNF system in the amygdala might contribute to explaining the onset of comorbid psychiatric disorders that persist in patients even beyond recovery from AN.

Restrained eating behaviour, anorexia nervosa and food consumption between children and adolescents: a scoping review

Anorexia nervosa (AN) and restrained eating behaviour (REB) are characterised by reduced food intake to achieve body weight loss. This scope review aimed to describe the existing evidence on the association between AN, restrictive eating behaviour and food consumption. Studies with children and adolescents of both sexes of all races and ethnicities were included. Experimental and observational studies, systematic reviews, meta-analysis, case reports or series, conference abstracts, dissertations and theses were also included. The search was conducted in ten electronic databases and grey literature without language restriction on 14 November 2020. Twenty-four studies met the inclusion criteria. Most studies included girls and identified lower intake of energy content, fat and certain micronutrients. There was also a higher intake of caffeine, fibre, vegetables, legumes and fruits and a lower intake of low-quality snack, fast food, sweets and foods with high carbohydrate and fat contents. The need to improve the quality of the diet among study participants was also identified. Thus, it is recommended that the evaluation of food consumption be careful to develop effective prevention strategies for the development of AN/REB and minimise nutritional deficiencies in these individuals.

Growth factors in anorexia nervosa: a systematic review and meta-analysis of cross-sectional and longitudinal data

OBJECTIVES

Growth factors are signalling molecules that play roles in the survival, proliferation, migration, and differentiation of cells. Studies have found alterations in specific growth factors in anorexia nervosa (AN).

METHODS

This systematic review and meta-analysis examined articles from three databases, measuring growth factors in AN cross-sectionally and longitudinally, and in recovered AN (rec-AN) cross-sectionally. Random-effects meta-analyses were conducted for brain-derived neurotrophic factor (BDNF) and insulin growth factor-I (IGF-1) for cross-sectional and longitudinal studies.

RESULTS

A total of 82 studies were included: 56 cross-sectional (BDNF: n = 15; IGF-1: n = 41) and 24 longitudinal (BDNF: n = 5; IGF-1: n = 19) were meta-analysed and 20 studies were narratively synthesised. In cross-sectional analyses, BDNF and IGF-1 were lower in AN compared to controls, and BDNF was marginally greater in rec-AN compared to controls. In longitudinal meta-analyses, BDNF and IGF-1 increased from baseline to follow-up. Cross-sectional subgroup analyses revealed no differences in BDNF between controls and AN binge-eating/purging subtypes.

CONCLUSIONS

It is likely that the low BDNF and IGF-1 levels found in AN are consequences of starvation, which are reversible with weight restoration. The increase in BDNF and IGF-1 during therapeutic weight restoration might improve neuroplasticity, which is the basis of learning, and thus psychotherapeutic success.

Apelin-13 and Asprosin in Adolescents with Anorexia Nervosa and Their Association with Psychometric and Metabolic Variables

Anorexia nervosa (AN) is a widespread, metabo-psychiatric disorder with high relapse rates, comorbidity, and mortality. Many regulatory proteins and neurohormones studied to date play essential roles in the etiopathogenesis of eating disorders and the maintenance of psychopathological symptoms. Nevertheless, the regulatory and pathophysiological mechanisms of AN are still poorly understood. In the presented study, the plasma levels of apelin-13 (APE-13) and asprosin (ASP), as well as carbohydrate metabolism parameters and psychometric parameters, were evaluated in low-weight adolescent female patients with AN (AN1), after partial weight normalization (AN2) and in an age-matched healthy control group (CG) were evaluated. APE-13 levels were higher in the AN1 group than in the post-realimentation and the CG group. APE-13 levels were independent of insulin and glucose levels. Plasma ASP levels increased with increasing body weight in patients with AN, correlating with the severity of eating disorder symptoms in emaciation. The presented data suggest that APE-13 and ASP may be AN’s biomarkers-regulation of eating behavior by APE-13 and ASP, the close relationship between them and emotional behavior, and changes in neurohormone levels in patients with eating and affective disorders seem to support these hypotheses. Moreover, their plasma levels seem to be related to the severity of psychopathological symptoms of eating disorders.

Ghrelin and Obestatin in Adolescent Patients with Anorexia Nervosa: Is There an Association with Disordered Eating, Depression, and Obsessive-Compulsive Symptoms?

Anorexia nervosa (AN) is an eating disorder characterized by restrictive eating and significant weight loss. In the course of AN, changes are observed in appetite regulation, including orexigenic ghrelin and potentially anorexigenic obestatin. The study aimed to determine if any changes in serum ghrelin and obestatin levels during treatment of AN are observed, while investigating the correlations between these peptides and the severity of disturbed eating attitudes, depression, and anxiety. Thirty adolescent inpatients with AN (examined twice: before hospitalization treatment AN-BT and after treatment AN-AT) and thirty healthy age- and height-matched girls (CG) participated in the study. Anthropometric, serum ghrelin and obestatin concentrations and psychometric evaluations (Eating Attitudes Test 26 Item-EAT-26, Beck Depression Inventory-BDI, Hamilton Depression Rating Scale-HDRS, and Yale Brown Obsessive-Compulsive Scale-Y-BOCS) were performed. The study revealed significantly higher ghrelin and obestatin levels in AN-BT than in AN-AT. A trend toward lower levels during treatment provided partial normalizations. Analyzing correlations in the AN-BT vs. CG group, correlations of peptides with EAT-26, BDI, and HDRS scores were detected. These results suggest a potential role for ghrelin and obestatin in the context of defense mechanisms regulating appetite and body weight in the course of AN and in terms of psychopathological changes co-occurring with this eating disorder.

Serum and plasma levels of brain-derived neurotrophic factor in individuals with eating disorders (EDs): a systematic review and meta-analysis

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is essential for neuronal survival, differentiation, development, and plasticity. Evidence suggests that fluctuations in peripheral levels (i.e., plasma or serum) of BDNF are associated with eating behaviors. Nevertheless, the findings are inconsistent. The purpose of this study is to determine if serum or plasma levels of BDNF are altered in individuals with eating disorders (EDs) compared to controls.

METHODS

We conducted a systematic search of the core electronic medical databases from inception to March 2022 and identified observational studies that compared individuals with EDs to controls without EDs on serum or plasma levels of BDNF. R version 4.0.4 was used for all visualizations and calculations.

RESULTS

The current meta-analysis comprised 15 studies that fulfilled the inclusion criteria. Subjects with EDs (n = 795) showed lower BDNF levels compared to non-EDs controls (n = 552) (SMD: - 0.49, 95% CI [- 0.89; - 0.08], p-value = 0.01). Moreover, subgroup analysis was conducted based on the specimen (plasma and serum), which revealed no statistically significant difference in the levels of BDNF between the two subgroups (p-value = 0.92). Additionally, meta-regression results revealed that publication year, mean age of the individuals with EDs, NOS scores, and the number of individuals with EDs collectively accounted for 25.99% percent of the existing heterogeneity.

CONCLUSION

Lower BDNF levels are associated with EDs.

Expression of immune-related proteins and their association with neuropeptides in adolescent patients with anorexia nervosa

Anorexia nervosa (AN) is a metabo-psychiatric disorder where alterations of cytokines, neuropeptides, neurotransmitters, and the interactions between these factors can play an important role. Thus, the primary goal of the presented study was a cross-sectional analysis of immune-related proteins in patients with AN. Moreover, the correlations between these molecules and selected neuropeptides were studied. Twenty-five adolescent inpatients girls in the acute stage of a restrictive type of AN were enrolled in the study within the first year of the disease. Additionally, thirty similar in age and height controls (CG) were also assessed. The levels of 24 immune-related proteins, including cytokines, chemokines, and proteases, were measured. Moreover, selected adipocytokines, gastrointestinal hormones, and centrally produced neuropeptides levels were determined. Finally, the correlations between these molecules were analyzed. The fasting levels of CXCL1, CXCL9, FGF2, GrB, IL1, IL6, IL8, MMP8, MMP9, CTSS were statistically lower in AN than in the CG. The concentrations of many immune-related proteins remain unchanged despite their metabolic and mental condition. Moreover, significant correlations were found between leptin and CXCL1, CXCL9, GrB, IL1, IL6, and MMP8. Leptin receptors were correlated with GrB, while resistin was associated with MMP9. Our findings suggest that the initial stage of restrictive AN among adolescents within the first year of the disease is not connected with a pro-inflammatory state. Some immune-related protein changes may be associated with altered neuropeptides, primarily leptin, its receptors, and resistin. Future research should clarify which changes are primary and secondary to weight loss and whether these changes normalize with increasing weight. This would aid in understanding the complex etiopathogenesis of AN and in the search for new methods of treatment.

BDNF levels in adolescent patients with anorexia nervosa increase continuously to supranormal levels 2.5 years after first hospitalization

BACKGROUND

Brain-derived neurotrophic factor (BDNF) influences brain plasticity and feeding behaviour, and it has been linked to anorexia nervosa in numerous studies. Findings in mostly adult patients point to reduced serum BDNF levels in the acute stage of anorexia nervosa and rising levels with weight recovery. However, it is unclear whether this increase leads to normalization or supranormal levels, a difference that is potentially important for the etiology of anorexia nervosa and relapse.

METHODS

We measured serum BDNF at admission (n = 149), discharge (n = 130), 1-year follow-up (n = 116) and 2.5-year follow-up (n = 76) in adolescent female patients with anorexia nervosa hospitalized for the first time, and in healthy controls (n = 79). We analyzed associations with body mass index, eating disorder psychopathology and comorbidities.

RESULTS

Serum BDNF was only nominally lower at admission in patients with anorexia nervosa compared to healthy controls, but it increased continuously and reached supranormal levels at 2.5-year follow-up. BDNF was inversely associated with eating disorder psychopathology at discharge and positively associated with previous weight gain at 1-year follow-up.

LIMITATIONS

We compensated for attrition and batch effects using statistical measures.

CONCLUSION

In this largest longitudinal study to date, we found only nonsignificant reductions in BDNF in the acute stage of anorexia nervosa, possibly because of a shorter illness duration in adolescent patients. Supranormal levels of BDNF at 2.5-year follow-up could represent a pre-existing trait or a consequence of the illness. Because of the anorexigenic effect of BDNF, it might play an important predisposing role for relapse and should be explored further in studies that test causality.

Effects of intranasal oxytocin in food intake and craving: A meta-analysis of clinical trials

OBJECTIVE

A rise of endogenous oxytocin (OT) is associated with anxiety and meal size reduction, and the effects of intranasal OT (INOT) have been examined in the management of food intake and craving. However, the discrepancy INOT effects in different disease populations are not entirely clear.

RESEARCH DESIGN AND METHODS

Updated systematic review and meta-analysis. By systematically searching the PubMed, Embase and Cochrane Library, we obtained 12 controlled trials. We performed meta-analyses to examine food intake, craving, anxiety or stress reduction on INOT administration, using standard mean difference (SMD) with a 95% confidence interval (CI) and a random-effects model.

RESULTS

This study examined 12 trials with 266 non-psychiatric and 157 psychiatric participants. The pooled results showed that single-dose INOT induced a significant lesser food intake in non-psychiatric subjects (SMD: -0.66 [95% CI: -1.18, -0.14]), but no effects was found in anorexia nervosa (AN) (SMD: 0.17 [95% CI: -0.32, 0.66]), bulimia nervosa (BN) and binge eating disorder (BED) (SMD: -0.41 [95% CI: -0.94, 0.11]), and schizophrenia (SMD: 0.04 [95% CI: -0.94, 1.02] subjects. Further analysis on leisure food also indicated an inhibition of consumption of chocolate biscuits in non-psychiatric subjects. Neither the non-psychiatric (SMD: -0.08 [95% CI: -0.50, 0.33]) nor the BN and BED (SMD: -0.08 [95% CI: -0.72, 0.88]) and schizophrenia subjects (SMD: -0.07 [95% CI: -1.05, 0.91]) demonstrated a difference in food craving or hunger compared with placebo. Anxiety or stress level was not influenced by INOT in any subgroup (non-psychiatric, SMD: 0.19 [95% CI: -0.22, 0.60]; AN, SMD: -0.01 [95% CI: -0.28, 0.88]; BN and BED: SMD: 0.00 [95% CI: -0.80, 0.80]).

CONCLUSIONS

Single-dose INOT significantly reduces food intake in nonpsychiatric subjects, and further studies are necessary to assess the long-term effects and safety in obese patients. Whether INOT could be a treatment option for patients with eating disorders remains to be investigated.

Adolescents With Autism Spectrum Disorder and Anorexia Nervosa Comorbidity: Common Features and Treatment Possibilities With Cognitive Remediation Therapy and Oxytocin

Autistic traits or autism spectrum disorder (ASD) can be found in 4% to 52% of anorexic patients, which makes the treatment of these patients very challenging. In this review, possible ways to treat ASD and anorexia nervosa (AN) comorbidity in children and adolescents are summarized. Over recent years, the focus has shifted from searching for the evidence of connections between these two disorders, which have started with Gillberg's study in 1983, to searching for more effective and holistic treatment of this comorbidity. The latter is known to contribute to more severe courses and worse prognosis, which is probably related to the obstacles in both diagnosing and treating. Since AN usually starts in early adolescence and high-functioning ASD children seem to begin struggling with increased pressure in adolescence, while various comorbidities can occur, it is important to improve the treatment of this comorbidity in young patients and to tailor it specifically in terms of diagnosing. In this paper, a literature review is conducted on common features and promising treatment possibilities. We describe cognitive remediation therapy and the promising pharmacotherapeutic candidate oxytocin with a special focus on adolescents.

Omentin and visfatin in adolescent inpatients with anorexia nervosa; association with symptoms

Anorexia nervosa (AN) is associated with significant weight loss; thus, it is crucial to discern the contribution of hormones produced by adipose tissue. Some of the adipokines have not been sufficiently studied. Therefore, the present study aims to measure serum concentrations of omentin and visfatin, in adolescent inpatients with AN. The correlations between selected adipokines and psychopathological symptoms of AN were also analyzed. Thirty adolescent inpatients with anorexia nervosa and thirty healthy age and height matched girls (CONT) were enrolled in the study. The physical and mental examination, anthropometric and psychometric assessment - Beck Depression Inventory (BDI), Hamilton Depression Rating Scale (HDRS), Eating Attitude Test (EAT-26) and Yale-Brown Obsessive-Compulsive Scale (YBOCS), and blood analysis were performed at two-time points - in the malnourished patients (AN T1) and after partial weight recovery (8.30 ± 3.75 weeks) (AN T2). The omentin concentration was not significantly different from the CONT neither in AN T1 nor AN T2. The visfatin level was altered in AN T1 and did not change after partial weight normalization (AN T2). A positive correlation between visfatin and YBOCS was found in AN T2. Visfatin concentrations were decreased in adolescent inpatients suffering from AN in the acute phase of the disease and did not normalize after partial weight restoration. The studies considering visfatin as a biomarker of the acute phase of AN should be continued. Moreover, the visfatin showed association with the obsessive and compulsive symptoms; thus its participation in non-homeostatic regulation of food intake should be investigated in further studies.

Is Serum BDNF Altered in Acute, Short- and Long-Term Recovered Restrictive Type Anorexia Nervosa?

Brain-derived neurotrophic factor (BDNF), a neurotrophin involved in the regulation of food intake and body weight, has been implicated in the development and maintenance of Anorexia nervosa (AN). The majority of previous studies reported lower BDNF levels in acutely underweight AN patients (acAN) and increasing levels after weight rehabilitation. Here, we investigated serum BDNF concentrations in the largest known AN sample to date, both before and after weight restoration therapy. Serum BDNF was measured in 259 female volunteers: 77 in-patient acAN participants of the restrictive type (47 reassessed after short-term weight rehabilitation), 62 individuals long-term recovered from AN, and 120 healthy controls. We validated our findings in a post-hoc mega-analysis in which we reanalyzed combined data from the current sample and those from our previous study on BDNF in AN (combined sample: 389 participants). All analyses carefully accounted for known determinants of BDNF (age, sex, storage time of blood samples). We further assessed relationships with relevant clinical variables (body-mass-index, physical activity, symptoms). Contrary to our hypotheses, we found zero significant differences in either cross-sectional or longitudinal comparisons and no significant relationships with clinical variables. Together, our study suggests that BDNF may not be a reliable state- or trait-marker in AN after all.