Inflammatory cytokines and anorexia nervosa: A meta-analysis of cross-sectional and longitudinal studies

Causal effects of gut microbiota, metabolites, immune cells, liposomes, and inflammatory proteins on anorexia nervosa: A mediation joint multi-omics Mendelian randomization analysis

BACKGROUND

Anorexia nervosa (AN) is a significant psychological disorder influenced by environmental and genetic elements. Emerging research highlights the pivotal role of the gut microbiome in the development of diverse mental health conditions. This study aims to explore the causal effects and interactions of the gut microbiome, metabolites, immune cells, lipids, and inflammatory proteins on the risk of anorexia nervosa through mediation and multi-omics Mendelian Randomization (MR) analysis.

METHODS

This study used data from the FinnGen genome-wide association study (GWAS) of AN (N = 402,625), integrated with GWAS data on 473 of gut microbiota (N = 5959), 233 metabolites (N = 136,016), 731 immune cells (N = 3757), 179 lipids (N = 7174), and 91 inflammatory proteins (N = 14,824). This study used the univariate MR (UVMR), mediation MR analysis, and sensitivity analysis to assess the potential causal associations between these biomarkers and AN.

RESULTS

The inverse variance weighted (IVW) results suggest that 25 gut microbiota have causal effects on AN. Firmicutes E (OR: 0.294, 95 % CI: 0.107-0.806, P = 0.017), RUG147 (OR: 0.386, 95 % CI: 0.151-0.990, P = 0.048), CAG-977 (OR: 0.562, 95 % CI: 0.378-0.837, P = 0.005), Desulfobacterota A (OR: 0.651, 95 % CI: 0.466-0.909, P = 0.012), CAG-269 sp002372935 (OR: 0.673, 95 % CI: 0.483-0.937, P = 0.019), Klebsiella (OR: 0.684, 95 % CI: 0.566-0.827, P = 0.00009), Desulfovibrionia (OR: 0.706, 95 % CI: 0.538-0.926, P = 0.012), Klebsiella pneumoniae (OR: 0.737, 95 % CI: 0.600-0.906, P = 0.004), Desulfovibrionales (OR: 0.786, 95 % CI: 0.631-0.979, P = 0.031), CAG-776 (OR: 0.787, 95 % CI: 0.632-0.980, P = 0.032), Desulfovibrionaceae (OR: 0.788, 95 % CI: 0.635-0.978, P = 0.030). 13 gut microbiota were risk factors for AN, including Parachlamydiales (OR: 3.134，95%CI: 1.185-8.287, P = 0.021), Paenibacillus J (OR: 2.366，95%CI: 1.305-4.29, P = 0.005), Gillisia (OR: 1.947，95%CI: 1.135-3.339, P = 0.016), UBA1191 (OR: 1.856，95%CI: 1.221-2.822, P = 0.004), UBA7703 (OR: 1.843，95%CI: 1.032-3.289, P = 0.039), Faecalicatena sp002161355 (OR: 1.788，95%CI: 1.114-2.870, P = 0.016), Johnsonella ignava (OR: 1.742，95%CI: 1.031-2.944, P = 0.038), Staphylococcus aureus (OR: 1.614, 95%CI: 1.007-2.588, P = 0.047), Comamonas (OR: 1.522，95%CI: 1.004-2.307, P = 0.048), Ruminococcus D (OR: 1.24，95%CI: 1.050-1.464, P = 0.011), CAG-349 (OR: 1.198，95%CI: 1.048-1.370, P = 0.008), Ruminococcus D bicirculans (OR: 1.175，95%CI: 1.001-1.379, P = 0.048), CAG-177 (OR: 1.272，95%CI: 1.077-1.503, P = 0.005). Reverse MR analysis showed that causal effect of AN on 18 gut microbiota, but to a lesser extent. 12 metabolites have causal effects on AN. There are 7 protective factors, including glucose levels (OR: 0.700, 95%CI: 0.550-0.893, P = 0.004), isoleucine levels (OR: 0.769, 95%CI: 0.602-0.983, P = 0.036), phospholipids in large VLDL (OR: 0.856, 95%CI: 0.736-0.996, P = 0.044), total lipids in large VLDL (OR: 0.860, 95%CI: 0.740-0.999, P = 0.049), total lipids in small VLDL (OR: 0.863, 95%CI: 0.751-0.992, P = 0.038), free cholesterol in small VLDL (OR: 0.86, 95%CI: 0.752-0.996, P = 0.044), and free cholesterol in medium VLDL (OR: 0.866, 95%CI: 0.752-0.998, P = 0.047). There are 5 risk factors, including estimated degree of unsaturation (OR: 1.174, 95%CI: 1.009-1.367, P = 0.039), free cholesterol to total lipids ratio in small VLDL (OR: 1.199, 95%CI: 1.017-1.414, P = 0.031), phospholipids to total lipids ratio in small VLDL (OR: 1.216, 95%CI: 1.008-1.467, P = 0.041), total cholesterol levels in small HDL (OR: 1.241, 95%CI: 1.008-1.530, P = 0.042), and phospholipids to total lipids ratio in medium VLDL (OR: 1.280, 95%CI: 1.055-1.553, P = 0.012). Reverse MR analysis showed that AN had a causal effect on 15 metabolites. Mediation analysis reveals that the estimated degree of unsaturation mediates 0.69 % of the effect of Klebsiella pneumoniae on AN. Total lipids in small VLDL mediate 0.358 % of the effect of CAG-177 on AN, with a mediated proportion of 1.490 %. The mediation proportions for Estimated degree of unsaturation and Total lipids in small VLDL are relatively small. 36 immune cells have causal effects on AN. There are 7 protective factors, including Switched memory B cells %B cell (OR: 0.892，95%CI: 0.801-0.994, P = 0.038), CD127-CD8+ T cell absolute count (OR: 0.888，95%CI: 0.789-1.000, P = 0.049), IgD + CD24- B cell (OR: 0.917，95%CI: 0.862-0.975, P = 0.006), HVEM+ T cell (OR: 0.945，95%CI: 0.894-0.999, P = 0.045), CD40 + CD14 + CD16- monocyte (OR: 0.937，95%CI: 0.882-0.996, P = 0.038), CD64 + CD14 + CD16- monocyte (OR: 0.966，95%CI: 0.939-0.993, P = 0.016), CD8+ natural killer T cells (OR: 0.911，95%CI: 0.836-0.992, P = 0.032), HLA-DR+ T cells (OR: 0.921，95%CI: 0.866-0.980, P = 0.010), CD28-CD8+ T cells (OR: 0.886，95%CI: 0.792-0.991, P = 0.034). There are 26 risk factors. Reverse MR analysis showed that AN had a causal effect on 31 immune cells. AN increases the expression levels of five types of immune cells, including CD40 + CD14-CD16+ monocytes (OR: 1.087，95%CI: 1.004-1.177, P = 0.041), PDL-1+ CD14-CD16+ monocytes (OR: 1.082，95%CI: 1.002-1.168, P = 0.046), CD45+ CD33dim HLA-DR+ cells (OR: 1.145，95%CI: 1.019-1.287, P = 0.023), CD45+ basophils (OR: 1.164，95%CI: 1.036-1.307, P = 0.011), CD8+ natural killer T cells (OR: 1.102, 95%CI: 1.015-1.196, P = 0.020), and also decreases the expression levels of 26 immune cells. 6 liposomes showed exhibit protective effects against AN, including phosphatidylcholine (18:0_20:3) levels (OR: 0.852, 95%CI: 0.740-0.981, P = 0.026), phosphatidylcholine (O-18:2_18:1) levels (OR: 0.800, 95%CI: 0.672-0.952, P = 0.012), phosphatidylinositol (18:0_18:1) levels (OR: 0.873, 95%CI: 0.773-0.986, P = 0.029), phosphatidylinositol (18:1_18:2) levels (OR: 0.844, 95%CI: 0.734-0.971, P = 0.018), sphingomyelin (d38:1) levels (OR: 0.903，95%CI: 0.820-0.995, P = 0.039), and triacylglycerol (56:4) levels (OR: 0.786, 95%CI: 0.660-0.936, P = 0.007). There are 3 risk factors, including diacylglycerol (16:1_18:1) levels (OR: 1.208, 95%CI: 1.040-1.404, P = 0.014), phosphatidylcholine (18:1_18:3) levels (OR: 1.237, 95%CI: 1.003-1.526, P = 0.047), and phosphatidylinositol (16:0_20:4) levels (OR: 1.148, 95%CI: 1.003-1.314, P = 0.045). Reverse MR analysis showed that AN had a causal effect on 3 phosphatidylcholine (15:0_18:2) levels (OR: 1.075, 95%CI: 1.001-1.154, P = 0.048), phosphatidylcholine (O-16:2_18:0) levels (OR: 1.078, 95%CI: 1.002-1.159, P = 0.043), and triacylglycerol (51:1) levels (OR: 0.919, 95%CI: 0.850-0.994, P = 0.035). 6 inflammatory proteins have causal effects on AN, with protective factors including Glial cell line-derived neurotrophic factor levels (OR: 0.822，95%CI: 0.692-0.978, P = 0.027) and Interleukin-15 receptor subunit alpha levels (OR: 0.886, 95%CI: 0.789-0.995, P = 0.041) and risk factors including CC motif chemokine 4 levels (OR: 1.126, 95%CI: 1.011-1.254, P = 0.031), Interleukin-12 subunit beta levels (OR: 1.135, 95%CI: 1.033-1.248, P = 0.008), Monocyte chemoattractant protein-1 levels (OR: 1.152, 95%CI: 1.010-1.314, P = 0.035), and Sulfotransferase 1A1 levels (OR: 1.166, 95%CI: 1.006-1.351, P = 0.042). Reverse MR analysis showed that AN had a causal effect on Transforming growth factor-alpha (OR: 1.054，95%CI: 1.010-1.101, P = 0.016).

CONCLUSIONS

This study used large-scale and novel GWAS data, for the first time reveals through mediation analysis and multi-omics MR analysis the roles of gut microbiota, metabolites, immune cells, lipids, and inflammatory proteins in the pathogenesis of AN. These findings provide new biomarkers and targets for further prevention and treatment strategies.

C-reactive protein (CRP) levels in people with eating disorders: A systematic review and meta-analysis

Studies suggest that there is a relationship between inflammatory diseases, inflammatory markers such as C-reactive protein (CRP) and psychiatric disorders. In eating disorders, cross-sectional studies have recently examined peripheral CRP levels in blood serum and plasma, which allow a comprehensive meta-analysis. This systematic review and meta-analysis examined studies from three databases, measuring CRP levels in people with eating disorders, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A total n = 14 publications were included into the systematic review. Of these, n = 13 cross-sectional papers with N = 700 participants were meta-analysed, n = 11 in anorexia nervosa (AN) and n = 2 in binge eating disorder (BED). One study of the total n = 14 was narratively summarised because it was not suitable for inclusion into the meta-analysis. In the cross-sectional analyses, CRP levels were significantly lower in people with AN compared to health controls (HCs), but CRP level were higher in people with BED compared to HCs. Patients with AN appear to have lower CRP levels compared to healthy controls. This could be a result of malnutrition or specific nutritional deficiencies. Due to the reduced CRP levels in AN, patients might be at risk for bacterial infections or developing autoimmune diseases, and clinicians might fail to notice an inflammatory process or an infection. In contrast, patients with BED were found to have higher CRP level than healthy controls which might be a consequence of an inflammatory response triggered by overeating, disordered eating patterns and the consumption of low-quality food during binges.

Activity-based anorexia (ABA) model: Effects on brain neuroinflammation, redox balance and neuroplasticity during the acute phase

Several evidences suggest that immuno-inflammatory responses are involved in the pathogenesis of anorexia nervosa (AN). Herein we investigate the possible alteration of key mediators of inflammation, redox balance, and neuroplasticity in the brain of rats showing an anorexic-like phenotype. We modeled AN in adolescent female rats using the activity-based anorexia (ABA) paradigm and measured gene expression levels of targets of interest in the prefrontal cortex (PFC) and dorsal hippocampus (DH). We observed reduced mRNA levels of pro-inflammatory cytokines IL-1β and TNF-α, the inflammasome NLRP3, and the microglial marker CD11b in both PFC and DH of ABA animals. Conversely, the mRNA of IL-6, which acts as both a pro-inflammatory and anti-inflammatory cytokine, was increased. Moreover, we observed an overall upregulation of different antioxidant enzymes in PFC, while their profile was not affected or opposite in the DH, with the exception of MT1α. Interestingly, ABA animals showed elevated levels of the neuroplasticity marker BDNF in both PFC and DH. Our data indicate that ABA induction is associated with anatomical-specific cerebral alteration of mediators of neuroinflammation, oxidative balance and neuroplasticity. Although more research should be conducted, these results add important information about the role of these systems in the complex AN etiopathogenesis.

Novel treatments for anorexia nervosa: Insights from neuroplasticity research

OBJECTIVE

Treatment for anorexia nervosa (AN) remains challenging; there are no approved psychopharmacological interventions and psychotherapeutic strategies have variable efficacy. The investigation of evidence-based treatments has so far been compounded by an underdeveloped understanding into the neurobiological changes associated with the acute stages of AN. There is converging evidence of deficiencies in neuroplasticity in AN.

METHOD

This paper provides an overview of neuroimaging, neuropsychological, molecular and qualitative findings relating to neuroplasticity in AN, translating these findings to the identification of novel biological and psychotherapeutic strategies.

RESULTS

Novel psychopharmacological approaches that may ameliorate deficiencies in neuroplasticity include medications such as ketamine, psilocybin and human recombinant leptin. Anti-inflammatory medications and brain-derived neurotrophic factor mimetics may emerge as potential treatments following further research. Psychotherapeutic strategies that may target neuroplastic deficiencies, as well as having wider effects on identity, include imagery rescripting, memory specificity training, cognitive remediation therapy, exposure therapies, narrative therapies, cultural interventions (e.g. music and arts therapies) and yoga/mindfulness-based interventions.

CONCLUSIONS

Treatments specifically targeted towards mitigating the neurobiological sequalae of AN are warranted, and emerging neurobiological and neuropsychological research utilising longitudinal designs and large sample sizes, as well as initial feasibility studies, are necessitated to bolster translational efforts.

A transdiagnostic and diagnostic-specific approach on inflammatory biomarkers in eating disorders: A meta-analysis and systematic review

Eating disorders (EDs) are severe mental illnesses with a multifactorial etiology and a chronic course. Among the biological factors related to pathogenesis and maintenance of EDs, inflammation acquired growing scientific interest. This study aimed to assess the inflammatory profile of EDs, focusing on anorexia nervosa, bulimia nervosa, and including for the first time binge eating disorder. A comprehensive research of existing literature identified 51 eligible studies for meta-analysis, comparing levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), osteoprotegerin (OPG), soluble receptor activator of nuclear factor kappa-B ligand (sRANKL), interleukin-1β (IL-1β), and interleukin-10 (IL-10) between patients with EDs and healthy controls (HCs). The systematic review explored other inflammatory biomarkers of interest, which did not meet the meta-analysis criteria. Results revealed significantly elevated levels of TNF-α, OPG, sRANKL, and IL-1β in patients with EDs compared to HCs. Additionally, the results highlighted the heterogeneity of inflammatory state among patients with EDs, emphasizing the need for further research into the association between inflammatory biomarkers and psychopathological correlates. This approach should transcend categorical diagnoses, enabling more precise subcategorizations of patients. Overall, this study contributed to the understanding of the inflammatory pathways involved in EDs, emphasizing potential implications for diagnosis, staging, and targeted interventions.

Structural connectivity modifications following deep brain stimulation of the subcallosal cingulate and nucleus accumbens in severe anorexia nervosa

PURPOSE

Anorexia nervosa (AN) is a mental health disorder characterized by significant weight loss and associated medical and psychological comorbidities. Conventional treatments for severe AN have shown limited effectiveness, leading to the exploration of novel interventional strategies, including deep brain stimulation (DBS). However, the neural mechanisms driving DBS interventions, particularly in psychiatric conditions, remain uncertain. This study aims to address this knowledge gap by examining changes in structural connectivity in patients with severe AN before and after DBS.

METHODS

Sixteen participants, including eight patients with AN and eight controls, underwent baseline T1-weigthed and diffusion tensor imaging (DTI) acquisitions. Patients received DBS targeting either the subcallosal cingulate (DBS-SCC, N = 4) or the nucleus accumbens (DBS-NAcc, N = 4) based on psychiatric comorbidities and AN subtype. Post-DBS neuroimaging evaluation was conducted in four patients. Data analyses were performed to compare structural connectivity between patients and controls and to assess connectivity changes after DBS intervention.

RESULTS

Baseline findings revealed that structural connectivity is significantly reduced in patients with AN compared to controls, mainly regarding callosal and subcallosal white matter (WM) tracts. Furthermore, pre- vs. post-DBS analyses in AN identified a specific increase after the intervention in two WM tracts: the anterior thalamic radiation and the superior longitudinal fasciculus-parietal bundle.

CONCLUSIONS

This study supports that structural connectivity is highly compromised in severe AN. Moreover, this investigation preliminarily reveals that after DBS of the SCC and NAcc in severe AN, there are WM modifications. These microstructural plasticity adaptations may signify a mechanistic underpinning of DBS in this psychiatric disorder.

Therapeutic ketogenic diet as treatment for anorexia nervosa

Anorexia nervosa (AN) is a severe psychiatric disorder. However, we lack neurobiological models and interventions to explain and treat the core characteristics of food restriction, feeling fat, and body size overestimation. Research has made progress in understanding brain function involved in the pathophysiology of AN, but translating those results into biological therapies has been challenging. Studies have suggested that metabolic factors could contribute to developing and maintaining AN pathophysiology. Here, we describe a neurobiological model for why using a therapeutic ketogenic diet could address key alterations in brain function in AN and prevent the desire for weight loss and associated eating disorder-specific symptoms. This translational model is based on animal studies and human data and integrates behavioral traits, brain neural energy metabolism, and neurotransmitter function. Pilot data indicate that the intervention can dramatically reduce eating and body-related fears, although larger studies across illness stages still need to be conducted.

Sirtuin 1 as a potential biomarker of undernutrition in the elderly: a narrative review

Undernutrition and inflammatory processes are predictors of early mortality in the elderly and require a rapid and accurate diagnosis. Currently, there are laboratory markers for assessing nutritional status, but new markers are still being sought. Recent studies suggest that sirtuin 1 (SIRT1) has the potential to be a marker for undernutrition. This article summarizes available studies on the association of SIRT1 and undernutrition in older people. Possible associations between SIRT1 and the aging process, inflammation, and undernutrition in the elderly have been described. The literature suggests that low SIRT1 levels in the blood of older people may not be associated with physiological aging processes, but with an increased risk of severe undernutrition associated with inflammation and systemic metabolic changes.

Identification of State Markers in Anorexia Nervosa: Replication and Extension of Inflammation-Associated Biomarkers Using Multiplex Profiling

Background

Proteomics offers potential for detecting and monitoring anorexia nervosa (AN) and its variant, atypical AN (atyp-AN). However, research has been limited by small protein panels, a focus on adult AN, and lack of replication.

Methods

In this study, we performed Olink multiplex profiling of 92 inflammation-related proteins in females with AN/atyp-AN (n = 64), all of whom were ≤90% of expected body weight, and age-matched healthy control individuals (n = 44).

Results

Five proteins differed significantly between the primary AN/atyp-AN group and the healthy control group (lower levels: HGF, IL-18R1, TRANCE; higher levels: CCL23, LIF-R). The expression levels of 3 proteins (lower IL-18R1, TRANCE; higher LIF-R) were uniquely disrupted in participants with AN in our primary model. No unique expression levels emerged for atyp-AN. In the total sample, 12 proteins (ADA, CD5, CD6, CXCL1, FGF-21, HGF, IL-12B, IL18, IL-18R1, SIRT2, TNFSF14, TRANCE) were positively correlated with body mass index and 5 proteins (CCL11, FGF-19, IL8, LIF-R, OPG) were negatively correlated with body mass index in our primary models.

Conclusions

Our results replicate the results of a previous study that demonstrated a dysregulated inflammatory status in AN and extend those results to atyp-AN. Of the 17 proteins correlated with body mass index, 11 were replicated from a previous study that used similar methods, highlighting the promise of inflammatory protein expression levels as biomarkers of AN disease monitoring. Our findings underscore the complexity of AN and atyp-AN by highlighting the inability of the identified proteins to differentiate between these 2 subtypes, thereby emphasizing the heterogeneous nature of these disorders.

Effect of serum concentrations of IL-6 and TNF-α on brain structure in anorexia nervosa: a combined cross-sectional and longitudinal study

Previous studies of brain structure in anorexia nervosa (AN) have reported reduced gray matter in underweight patients, which largely normalizes upon weight gain. One underlying biological mechanism may be glial cell alterations related to low-grade inflammation. Here, we investigated relationships between brain structure as measured by magnetic resonance imaging and serum concentrations of two pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor alpha) cross-sectionally in 82 underweight adolescent and young adult female patients (mean age 16.8 years; 59 of whom were observed longitudinally after short-term weight restoration; mean duration 2.8 months), 20 individuals long-term weight-recovered from AN (mean age 22.7 years) and 105 healthy control (HC) participants (mean age 17.2 years). We measured cortical thickness, subcortical volumes and local gyrification index, a measure of cortical folding. In contrast to most previous studies of cytokine concentrations in AN, we found no cross-sectional group differences (interleukin-6: p = 0.193, tumor necrosis factor alpha: p = 0.057) or longitudinal changes following weight restoration (interleukin-6: p = 0.201, tumor necrosis factor alpha: p = 0.772). As expected, widespread gray matter reductions (cortical thickness, subcortical volumes, cortical folding) were observed in underweight patients with AN compared to HC. However, we found no evidence of associations between cytokine concentrations and structural brain measures in any participant group. Furthermore, longitudinal changes in cytokine concentrations were unrelated to changes in gray matter. In conclusion, we did not identify any association between (sub-)inflammatory processes and structural brain changes in AN. Future studies are needed to elucidate which other factors besides nutritional status may contribute to brain morphological alterations.

Pro-inflammatory cytokine alterations in recent onset anorexia nervosa adolescent female patients before and after 6 months of integrated therapy: A case-control study

Anorexia nervosa (AN) is a complex disorder affecting mainly, but not only, teenagers. Researchers agree that AN is deeply associated with a pro-inflammatory state following an impaired immune system, resulting from altered levels of cytokines such as IL-1β and TNF-α, also impacted by the frequent depressive states. Thus, this case-control study aimed to evaluate the relationship between patients suffering from AN undergoing specialized eating disorder treatment for AN and pro-inflammatory cytokines. To reach our purpose, we assessed eating-related psychopathology and depressive symptoms and measured serum concentration of pro-inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α before and after 6 months of integrated therapy (which included psychopharmacotherapy, psychotherapy, and nutritional treatment), to define whether selected pro-inflammatory cytokines could be considered a pathophysiological marker of the disorder. A sample of 16 young female patients with early diagnosis of AN, and without any previous treatment, and 22 healthy controls matched by age, sex, and socioeconomic status were enrolled. After 6 months of integrated therapy, a significant decrease of all selected pro-inflammatory cytokines was detected. In addition, an improvement in the anxiety-depressant aspects was also noted. In conclusion, the results obtained suggest that pro-inflammatory cytokines are indeed related to the pathophysiology of AN. However, further investigations, involving larger samples of patients with distinct subtypes of AN, are essential to confirm the current findings.

Longitudinal changes in brain-derived neurotrophic factor (BDNF) but not cytokines contribute to hippocampal recovery in anorexia nervosa above increases in body mass index

BACKGROUND

Physical sequelae of anorexia nervosa (AN) include a marked reduction in whole brain volume and subcortical structures such as the hippocampus. Previous research has indicated aberrant levels of inflammatory markers and growth factors in AN, which in other populations have been shown to influence hippocampal integrity.

METHODS

Here we investigated the influence of concentrations of two pro-inflammatory cytokines (tumor necrosis factor-alpha [TNF-α] and interleukin-6 [IL-6]) and brain-derived neurotrophic factor (BDNF) on the whole hippocampal volume, as well as the volumes of three regions (the hippocampal body, head, and tail) and 18 subfields bilaterally. Investigations occurred both cross-sectionally between acutely underweight adolescent/young adult females with AN (acAN; n = 82) and people recovered from AN (recAN; n = 20), each independently pairwise age-matched with healthy controls (HC), and longitudinally in acAN after partial renourishment (n = 58). Hippocampal subfield volumes were quantified using FreeSurfer. Concentrations of molecular factors were analyzed in linear models with hippocampal (subfield) volumes as the dependent variable.

RESULTS

Cross-sectionally, there was no evidence for an association between IL-6, TNF-α, or BDNF and between-group differences in hippocampal subfield volumes. Longitudinally, increasing concentrations of BDNF were positively associated with longitudinal increases in bilateral global hippocampal volumes after controlling for age, age2, estimated total intracranial volume, and increases in body mass index (BMI).

CONCLUSIONS

These findings suggest that increases in BDNF may contribute to global hippocampal recovery over and above increases in BMI during renourishment. Investigations into treatments targeted toward increasing BDNF in AN may be warranted.

Peripheral Biomarkers of Anorexia Nervosa: A Meta-Analysis

The pathogenesis of anorexia nervosa (AN) has been hypothesized to involve several biological systems. However, reliable biomarkers for AN have yet to be established. This study was aimed to identify statistically significant and clinically meaningful peripheral biomarkers associated with AN. A systematic literature search was conducted to identify studies published in English from inception until 30 June 2022. We conducted two-level random-effects meta-analyses to examine the difference between AN and comparison groups across 52 distinct biomarkers and found that acylated ghrelin, adrenocorticotropic hormone (ACTH), carboxy-terminal collagen crosslinks (CTX), cholesterol, cortisol, des-acyl ghrelin, ghrelin, growth hormone (GH), obestatin, and soluble leptin receptor levels were significantly higher in cases of AN compared with those in non-AN controls. Conversely, C-reactive protein (CRP), CD3 positive, CD8, creatinine, estradiol, follicle-stimulating hormone (FSH), free thyroxine, free triiodothyronine, glucose, insulin, insulin-like growth factor 1 (IGF-1), leptin, luteinizing hormone, lymphocyte, and prolactin levels were significantly lower in AN compared with those in non-AN controls. Our findings indicate that peripheral biomarkers may be linked to the pathophysiology of AN, such as processes of adaptation to starvation. Scientific investigation into peripheral biomarkers may ultimately yield breakthroughs in personalized clinical care for AN.

Cytokine and Microbiome Changes in Adolescents with Anorexia Nervosa at Admission, Discharge, and One-Year Follow-Up

Anorexia nervosa (AN) is a severe eating disorder that predominantly affects females and typically manifests during adolescence. There is increasing evidence that serum cytokine levels are altered in individuals with AN. Previous research has largely focused on adult patients, assuming a low-grade pro-inflammatory state. The serum levels of the cytokine tumour necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-6 and IL-15, which are pro-inflammatory, were examined in 63 female adolescents with AN and 41 age-matched healthy controls (HC). We included three time points (admission, discharge, and 1-year follow-up) and investigated the clinical data to assess whether the gut microbiota was associated with cytokine alterations. Relative to the HC group, serum levels of IL-1β and IL-6 were significantly lower during the acute phase (admission) of AN. IL-1β expression was normalised to control levels after weight recovery. TNF-α levels were not significantly different between the AN and HC groups. IL-15 levels were significantly elevated in patients with AN at all time points. We found associations between cytokines and bodyweight, illness duration, depressive symptoms, and the microbiome. In contrast to most findings for adults, we observed lower levels of the pro-inflammatory cytokines IL-1β and IL-6 in adolescent patients, whereas the level of IL-15 was consistently increased. Thus, the presence of inflammatory dysregulation suggests a varied rather than uniform pro-inflammatory state.

Serum peripheral markers for inflammation in adolescents with anorexia nervosa

BACKGROUND

There is a limited number of studies comparing the levels of inflammation in adolescent patients with anorexia nervosa (AN) and healthy controls based on complete blood count and platelet parameters.

METHODS

This study is a retrospective cross-sectional analysis of 53 drug-naive patients with AN and 53 healthy controls.

RESULTS

Significant differences were observed for WBC (white blood cell), neutrophil, MCV (mean corpuscular volume), MCH (mean corpuscular haemoglobin) and neutrophils/lymphocytes ratio (NLR) between the study groups. Patients with AN had lower WBC, neutrophiles and NLR values. But there was no difference between the groups in terms of inflammation-related platelet parameters. A strong positive correlation between BMI (body mass index) and PLT (platelet), PCT (plateletcrit) was determined in the patient group (r = 0.454, p = 0.001; r = 0.386, p = 0.007). Inflammation-related parameters may increase as BMI increases with nutrition and weight restoration.

CONCLUSIONS

The present study provides further evidence for level of inflammation in these patients does not increase during the acute period, unlike other mental diseases.

Reduction in Pappalysin-2 Levels and Lower IGF-I Bioavailability in Female Adolescents With Anorexia Nervosa

CONTEXT

Anorexia nervosa (AN) can cause severe undernutrition associated with alterations in the IGF axis. Pappalysins (PAPP-A, PAPP-A2) and stanniocalcins (STC-1, STC-2) modulate IGF binding-protein (IGFBP) cleavage and IGF bioavailability, but their implications in AN are unknown.

OBJECTIVE

We determined serum levels of PAPP-As and STCs in relationship with classical IGF axis parameters in female adolescents with AN and their association with nutritional status and secondary amenorrhea.

METHODS

Parameters of the IGF axis were determined in fasting serum samples of 68 female adolescents with AN at diagnosis and 62 sex- and age-matched controls. Standardized body mass index (BMI) and bone mineral density (BMD) were calculated.

RESULTS

Patients with AN had lower concentrations of total and free IGF-I, total IGFBP-3, acid-labile subunit (ALS), insulin, PAPP-A2, STC-1, and STC-2 and higher levels of IGF-II and IGFBP-2. Their free/total IGF-I ratio was decreased and the intact/total IGFBP-3 and -4 ratios increased. BMI was directly related to total IGF-I and intact IGFBP-3 and inversely with IGFBP-2 and intact IGFBP-4. Weight loss was directly correlated with intact IGFBP-4 and negatively with intact IGFBP-3, ALS, STC-2, and PAPP-A2 concentrations. BMD was directly related to intact IGFBP-3 and inversely with intact IGFBP-4 and PAPP-A2 levels. Patients with amenorrhea had lower levels of total IGF-I and IGFBP-3 than those with menses.

CONCLUSION

The reduction of PAPP-A2 in patients with AN may be involved in a decline in IGFBP cleavage, which could underlie the decrease in IGF-I bioavailability that is influenced by nutritional status and amenorrhea.

Carotid wave analysis in young adults with a history of adolescent anorexia nervosa: a case control study

BACKGROUND

Anorexia nervosa (AN) is associated with abnormalities that may increase the risk of future cardiovascular disease. This study assessed the cardiovascular health of individuals who recovered from AN during adolescence by conducting wave power analysis.

METHODS

Former AN patients discharged from the Royal Children's and Monash Children's Hospitals (N = 17) in Melbourne, Australia underwent ultrasound imaging of the right carotid artery. Wave power analysis was conducted to assess biomechanical interactions of the cardiovascular system. Patient measures were compared to healthy controls (N = 51).

RESULTS

Eighty-eight percent of the former AN patients and controls were female, aged approximately 25 years, with a healthy body mass index. Mean carotid flow and pulsatility index were not different between groups. Carotid arterial strain and distensibility were lower, and the wave speed and beta stiffness index higher in the former AN patients. Characteristic impedance was not different nor were the forward and backward wave amplitudes. However, wave reflection indices (ratios of backward-to-forward compression wave area, and wave-related effect on pressure and hydraulic power) were 12-18% lower in the former AN patients (p < 0.05).

CONCLUSIONS

Increased carotid artery stiffness and reduced wave reflection are evident in young adults who recovered from adolescent AN. This may relate to an adaptive process that helps to maintain or restore flow and characteristic impedance despite increased vessel stiffness, with this warranting future investigation.

Antiarthritic and Anti-Inflammatory Properties of Cannabis sativa Essential Oil in an Animal Model

Arthritis and inflammatory conditions require effective therapies, but conventional drugs have side effects. This study explored Cannabis sativa L. essential oil (CSEO) as a safer alternative. A chemical characterization of EO conducted via GC/MS showed the presence of sesquiterpene hydrocarbons (67.63%), oxygenated sesquiterpenes (25.91%), and oxygenated monoterpenes (0.99%). The study used three established inflammation induction tests: xylene-induced ear swelling, carrageenan-induced paw inflammation, and inflammation in the paw induced by Freund's complete adjuvant (CFA). Xylene triggered acute inflammation in the ear, while carrageenan-induced acute inflammatory responses through edema and immune-cell recruitment in the paw. CFA-induced arthritis simulated chronic inflammatory conditions. The obtained results demonstrated that treatment with CSEO significantly reduced ear weight in the xylene-induced ear-swelling test, indicating potential inhibition of neutrophil accumulation. In the carrageenan-induced paw inflammation test, CSEO reduced paw volume, suggesting interference with edema formation and leukocyte migration. In the CFA-induced paw inflammation test, CSEO decreased contralateral paw volume, restored body weight, and reduced C-reactive protein levels. Conclusion: this study provides compelling evidence supporting the antiarthritic and anti-inflammatory effects of CSEO. The findings indicate the therapeutic value of EO in the management of arthritis and inflammatory diseases while highlighting the need for further in-depth research to study the molecular mechanisms and validate their safety and efficacy for clinical applications. Preliminary data from this study suggests encouraging prospects for advancing the treatment and prevention of inflammation.

Anorexia Nervosa in vivo cytokine production: a systematic review

INTRODUCTION

The underlying psychobiology that contributes to Anorexia Nervosa (AN) onset and disease progression remains unclear. New research is emerging suggesting a possible link between inflammation and a variety of mental illnesses. Alterations of cytokines may play a role in the pathogenesis of AN. Some studies have found differences in the cytokine profile of those with AN compared to healthy controls, but results are heterogeneous. The aim of this work was to systematically review existing studies investigating in-vivo cytokine production in those with AN before and after weight restoration compared to controls.

METHODS

A comprehensive literature search of four electronic databases (PubMed, PsychInfo, EMBASE and CINAH) was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify human in-vivo studies investigating the relationship between AN and cytokine production. Data extracted from included studies related to population characteristics (e.g. age, gender, mean mBMI/%IBW), cytokine measurement and relevant findings. Confounding factors (e.g. smoking status, co-morbid mental illness, menstruation status) were also collected.

RESULTS

36 studies were eligible for this systematic review of which the majority were conducted in Europe (77.8%) and involved female subjects (97.2%). Those with AN ranged in age from 13 to 47 years and had an illness duration of 3 months to 24 years. 15 candidate cytokines and 3 receptors were identified (TNF-alpha, IL-6, IL-1B, CRP, IL-2, IL-7, IL-10, IFN-γ, TNF-R2, IL-1 α, IL-15, TNF-R1, IL-17, IL-18, TGF-B1, IL-12, IL-6R and TGF-B2) exploring in-vivo levels in patients with AN and comparing to controls. TNF-alpha and IL-6 were the most extensively studied with IL-6 being significantly elevated in 4 out of 8 (50%) of longitudinal studies when comparing AN patients at baseline compared to post weight restoration. Following weight restoration, there was no difference in IL-6 levels when comparing to HC in 7 of 8 (87.5%) longitudinal studies examined.

CONCLUSIONS

The most promising cytokine potentially involved in the pathogenesis of AN appears to be IL-6, and possibly TNF-alpha pathways. The heterogeneity of clinical and methodology factors impedes the generalizability of results. Future studies may wish to address these methodological shortcomings as alterations in cytokine levels in AN could act as therapeutic targets assisting with weight restoration and psychopathology and may offer diagnostic potential.

Microbiota in anorexia nervosa: potential for treatment

Anorexia nervosa (AN) is characterised by the restriction of energy intake in relation to energy needs and a significantly lowered body weight than normally expected, coupled with an intense fear of gaining weight. Treatment of AN is currently based on psychological and refeeding approaches, but their efficacy remains limited since 40% of patients after 10 years of medical care still present symptoms of AN. The intestine hosts a large community of microorganisms, called the "microbiota", which live in symbiosis with the human host. The gut microbiota of a healthy human is dominated by bacteria from two phyla: Firmicutes and, majorly, Bacteroidetes. However, the proportion in their representation differs on an individual basis and depends on many external factors including medical treatment, geographical location and hereditary, immunological and lifestyle factors. Drastic changes in dietary intake may profoundly impact the composition of the gut microbiota, and the resulting dysbiosis may play a part in the onset and/or maintenance of comorbidities associated with AN, such as gastrointestinal disorders, anxiety and depression, as well as appetite dysregulation. Furthermore, studies have reported the presence of atypical intestinal microbial composition in patients with AN compared with healthy normal-weight controls. This review addresses the current knowledge about the role of the gut microbiota in the pathogenesis and treatment of AN. The review also focuses on the bidirectional interaction between the gastrointestinal tract and the central nervous system (microbiota-gut-brain axis), considering the potential use of the gut microbiota manipulation in the prevention and treatment of AN.

The Impact of Clinical Factors, Vitamin B12 and Total Cholesterol on Severity of Anorexia Nervosa: A Multicentric Cross-Sectional Study

Severe forms of Anorexia Nervosa (AN) are characterized by medical complications, psychiatric comorbidity, and high mortality. This study investigated potential associations between clinical/biological factors and the severity of AN, measured by the Body Mass Index (BMI). Red and white blood cells, hemoglobin, platelets, iron, vitamins D and B12, folate, and total cholesterol were measured in a mixed sample of 78 inpatients and outpatients. Linear regressions and one-way analyses of variance (ANOVAs) were carried out to evaluate the relationship between BMI and clinical/biochemical variables. BMI was significantly lower in hospitalized patients (F = 4.662; p = 0.034) and in those under pharmacological treatment (F = 5.733; p = 0.019) or poly-therapy (F = 5.635; p = 0.021). Higher vitamin B12 (β = -0.556, p < 0.001), total cholesterol (β = -0.320, p = 0.027), and later age at onset (with a trend towards significance) (β = -0.376, p = 0.058) were associated with a lower BMI. Increased total cholesterol and vitamin B12, later age at onset, current pharmacological treatment, and poly-therapy might be distinctive in patients with a lower BMI. In clinical practice, these findings may contribute to the early identification of AN patients at higher risk of developing complicated or chronic forms of the disorder. Further studies on larger samples are needed to identify potential predictive factors of AN severity in the framework of precision medicine.

Ankylosing spondylitis and psychiatric disorders in European population: a Mendelian randomization study

Background

Epidemiologic evidence has demonstrated a correlation between ankylosing spondylitis and psychiatric disorders. However, little is known about the common genetics and causality of this association. This study aimed to investigate the common genetics and causality between ankylosing spondylitis (AS) and psychiatric disorders.

Methods

A two-sample Mendelian Randomization (MR) analysis was carried out to confirm causal relationships between ankylosing spondylitis and five mental health conditions including major depressive disorder (MDD), anxiety disorder (AXD), schizophrenia (SCZ), bipolar disorder (BIP), and anorexia nervosa (AN). Genetic instrumental variables associated with exposures and outcomes were derived from the largest available summary statistics of genome-wide association studies (GWAS). Bidirectional causal estimation of MR was primarily obtained using the inverse variance weighting (IVW) method. Other MR methods include MR-Egger regression, Weighted Median Estimator (WME), Weighted Mode, Simple Mode, and Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO). Sensitivity analyses are conducted to estimate the robustness of MR results.

Results

The findings suggest that AS may be causally responsible for the risk of developing SCZ (OR = 1.18, 95% confidence interval = (1.06, 1.31), P = 2.58 × 10-3) and AN (OR = 1.32, 95% confidence interval = (1.07, 1.64), P = 9.43 × 10-3). In addition, MDD, AXD, SCZ, AN, and BIP were not inversely causally related to AS (all p > 0.05).

Conclusion

Our study provides fresh insights into the relationship between AS and psychiatric disorders (SCZ and AN). Furthermore, it may provide new clues for risk management and preventive interventions for mental disorders in patients with AS.

Impact of BMI z-score on left ventricular mechanics in adolescent girls

Background

Adolescent weight disorders ranging from anorexia nervosa (AN) to obesity (OB) can impact the heart by causing opposite alterations in its morphology, suggesting a direct impact of body mass index (BMI) on the heart. Cardiac function is relatively preserved as assessed by standard echocardiography. However, few studies have used 2D speckle-tracking echocardiography (2D-STE), which can detect subtle alterations of left ventricular (LV) function by evaluating deformations. This study aimed to assess the link between the BMI z-score of adolescent girls and myocardial function.

Methods

Ninety-one adolescent girls comprising 26 AN patients (age 14.6 ± 1.9 years), 28 OB patients (age 13.2 ± 1.4 years), and 37 controls (age 14.0 ± 2.0 years) underwent 2D-STE to assess LV morphology and myocardial global and regional deformations.

Results

The BMI z-score of our population ranged from -4.6 to 5.2. LV morphological remodeling was significantly and positively correlated with the BMI z-score (R2 = 0.456, p < 0.0001 for LV mass). Global longitudinal strain (LS) and regional LS recorded at the mid and apical levels were significantly correlated with the BMI z-score (R2 = 0.196, p = 0.0001 and R2 = 0.274, p < 0.0001, respectively, for apical and medial LS). Circumferential strains and twisting mechanics were not correlated with the BMI z-score. Fibrinogen and systolic blood pressure were the main variables explaining the alteration of LS.

Conclusion

We observed that the BMI z-score had an impact on LV mechanics, especially on medial and apical LS. Neither circumferential nor twisting mechanics were altered by the BMI z-score in adolescent girls.

Identification of State Markers in Anorexia Nervosa: Replication and Extension of Inflammation Associated Biomarkers Using Multiplex Profiling in Anorexia Nervosa and Atypical Anorexia Nervosa

Proteomics provides an opportunity for detection and monitoring of anorexia nervosa (AN) and its related variant, atypical-AN (atyp-AN). However, research to date has been limited by the small number of proteins explored, exclusive focus on adults with AN, and lack of replication across studies. This study performed Olink Proseek Multiplex profiling of 92 proteins involved in inflammation among females with AN and atyp-AN (N = 64), all < 90% of expected body weight, and age-matched healthy controls (HC; N=44). After correction for multiple testing, nine proteins differed significantly in the AN/atyp-AN group relative to HC group ( lower levels: CXCL1, HGF, IL-18R1, TNFSF14, TRANCE; higher levels: CCL23, Flt3L, LIF-R, MMP-1). The expression levels of three proteins ( lower IL-18R1, TRANCE; higher LIF-R) were uniquely disrupted in females with AN. No unique expression levels emerged for atyp-AN. Across the whole sample, twenty-one proteins correlated positively with BMI (ADA, AXIN1, CD5, CD244, CD40, CD6, CXCL1, FGF-21, HGF, IL-10RB, IL-12B, IL18, IL-18R1, IL6, LAP TGF-beta-1, SIRT2, STAMBP, TNFRSF9, TNFSF14, TRAIL, TRANCE) and six (CCL11, CCL23, FGF-19, IL8, LIF-R, OPG) were negatively correlated with BMI. Overall, our results replicate the prior study demonstrating a dysregulated inflammatory status in AN, and extend these results to atyp-AN (AN/atyp-AN all < 90% of expected body weight). Of the 27 proteins correlated with BMI, 18 were replicated from a prior study using similar methods, highlighting the promise of inflammatory protein expression levels as biomarkers of disease monitoring. Additional studies of individuals across the entire weight spectrum are needed to understand the role of inflammation in atyp-AN.

Gut-Associated Lymphatic Tissue in Food-Restricted Rats: Influence of Refeeding and Probiotic Supplementation

Anorexia nervosa (AN) is a severe and often chronic eating disorder that leads to alterations in the gut microbiome, which is known to influence several processes, such as appetite and body weight regulation, metabolism, gut permeability, inflammation, and gut-brain interactions. Using a translational activity-based anorexia (ABA) rat model, this study examined the effect of chronic food starvation, as well as multistrain probiotic supplementation and refeeding, on the structure of the gut and gut-associated lymphatic tissue (GALT). Our results indicated that ABA had an atrophic influence on intestinal morphology and increased the formation of GALT in the small bowel and colon. Higher formation of GALT in ABA rats appeared to be reversible upon application of a multistrain probiotic mixture and refeeding of the starved animals. This is the first time that increased GALT was found following starvation in the ABA model. Our results underscore a potential role of gut inflammatory alterations in the underlying pathophysiology of AN. Increased GALT could be linked to the gut microbiome, as probiotics were able to reverse this finding. These results emphasize the role of the microbiome-gut-brain axis in the pathomechanisms of AN and point to probiotics as potentially beneficial addendum in the treatment of AN.

Anorexia Nervosa in Juvenile Systemic Lupus Erythematosus (SLE): A Causality Dilemma

Juvenile-onset systemic lupus erythematosus (jSLE) is an autoimmune disorder with multifaceted clinical findings in different organ systems. Neuropsychiatric manifestations affect more than half of SLE patients, and there is increasing evidence that anorexia nervosa (AN), a feeding and eating disorder (FED) characterized by significantly reduced energy intake, is among them. Herein, a review of the literature on the potential association between jSLE and AN was performed. Reported clinical cases were identified, and putative pathophysiological mechanisms were sought that could potentially explain the observed relationship between these two pathological entities. Four reports of isolated cases and a case series including seven patients were identified. In this limited patient pool, the diagnosis of AN preceded that of SLE in the majority of cases, whereas in all cases both entities were diagnosed within a time span of two years. Many explanations for the observed relationships have been proposed. AN has been associated with the stress of chronic disease diagnosis; on the other hand, the chronic inflammation associated with AN may contribute to the development/appearance of SLE. Adverse childhood experiences, concentrations of leptin, shared autoantibodies, and genetic traits appear to be important factors in this well-established interplay. In essence, it seems important to increase clinician awareness of the concomitant development of AN and SLE and invite further research on the subject.

The role of the brain-derived neurotrophic factor (BDNF) in anorexia nervosa

The brain-derived neurotrophic factor (BDNF) is a growth factor belonging to the neurotrophin family which plays a pivotal role in the differentiation, survival, and plasticity of neurons in the central nervous system. Evidence suggests that BDNF is an important signal molecule in the regulation of energy balance and thus implicated in body weight control. The discovery of BDNF-expressing neurons in the paraventricular hypothalamus which is important in the regulation of energy intake, physical activity, and thermogenesis gives more evidence to the suggested participation of BDNF in eating behavior. Until now it remains questionable whether BDNF can be used as a reliable biomarker for eating disorders such as anorexia nervosa (AN) as available findings on BDNF levels in patients with AN are ambiguous. AN is an eating disorder characterized by a pathological low body weight in combination with a body image disturbance typically developing during adolescence. A severe drive for thinness leads to restrictive eating behavior often accompanied by physical hyperactivity. During therapeutic weight restoration an increase of BDNF expression levels seems desirable as it might improve neuronal plasticity and survival which is essential for learning processes and thereby essential for the success of the psychotherapeutic treatment of patients. On the contrary, the well-known anorexigenic effect of BDNF might favor relapse in patients as soon as the BDNF levels significantly increase during weight rehabilitation. The present review summarizes the association between BDNF and general eating behavior and especially focuses on the eating disorder AN. In this regard findings from preclinical AN studies (activity-based anorexia model) are outlined as well.

Clinical and Peripheral Biomarkers in Female Patients Affected by Anorexia: Does the Neutrophil/Lymphocyte Ratio (NLR) Affect Severity?

Anorexia Nervosa (AN) is a disabling disorder characterized by extreme weight loss and frequent chronicization, especially in its most severe forms. This condition is associated with a pro-inflammatory state; however, the role of immunity in symptom severity remains unclear. Total cholesterol, white blood cells, neutrophils, lymphocytes, platelets, iron, folate, vitamin D and B12 were dosed in 84 female AN outpatients. Mildly severe (Body Mass Index-BMI ≥ 17) versus severe (BMI < 17) patients were compared using one-way ANOVAs or χ² tests. A binary logistic regression model was run to investigate the potential association between demographic/clinical variables or biochemical markers and the severity of AN. Patients with severe anorexia (compared to mild forms) were older (F = 5.33; p = 0.02), engaged in more frequent substance misuse (χ² = 3.75; OR = 3.86; p = 0.05) and had a lower NLR (F = 4.12; p = 0.05). Only a lower NLR was predictive of severe manifestations of AN (OR = 0.007; p = 0.031). Overall, our study suggests that immune alterations may be predictive of AN severity. In more severe forms of AN, the response of the adaptive immunity is preserved, while the activation of the innate immunity may be reduced. Further studies with larger samples and a wider panel of biochemical markers are needed to confirm the present results.

Association of gut-specific non-inflammatory T lymphocytes with chronic anorexia nervosa and constitutional thinness

OBJECTIVE

Previous studies of AN showed low-grade inflammation. Are low-grade inflammation and circulating lymphocytes associated with chronic conditions?

METHOD

Peripheric blood cytokines were measured using Luminex™ technology in a chronic AN cohort (mean = 67.42 months), compared to Constitutional Thinness (CT), Constitutional Obesity (CO), and Healthy Controls (HC). Secondarily a prospective cohort of chronic AN (mean = 54.11 months) was recruited to compare the functional lymphocyte profile in blood by flow cytometry to CT and HC.

RESULTS

In the AN group, most cytokine concentrations were lower than in CT and HC groups. The IL-23 (98.02 pg/ml) was elevated related to HC and CO, and the IL-10 (4.178 pg/ml) was elevated versus CO. In the CT group, IL-9 (0.06216 pg/ml) was elevated compared to AN. The AN group had high Treg (9.259% of CD4⁺ ) and CD8⁺ Integrinβ7⁺ (9.552% of CD3⁺ ) versus HC for lymphocyte populations. In CT group, elevated Treg (9.7% of CD4⁺ ) elevated percentage of CD4⁺ CCR9⁺ (5.867% of CD3⁺ ) and CD8⁺ Integrinβ7⁺ (10.21% of CD3⁺ ) were found versus HC.

CONCLUSIONS

The chronic state of AN and CT is surprisingly non-inflammatory with elevated Treg cells. These results suggest that maintaining a dysregulated response to intestinal antigens may contribute to maintaining AN.

Ketamine and Zinc: Treatment of Anorexia Nervosa Via Dual NMDA Receptor Modulation

Anorexia nervosa is a disorder associated with serious adverse health outcomes, for which there is currently considerable treatment ineffectiveness. Characterised by restrictive eating behaviours, distorted body image perceptions and excessive physical activity, there is growing recognition anorexia nervosa is associated with underlying dysfunction in excitatory and inhibitory neurometabolite metabolism and signalling. This narrative review critically explores the role of N-methyl-D-aspartate receptor-mediated excitatory and inhibitory neurometabolite dysfunction in anorexia nervosa and its associated biomarkers. The existing magnetic resonance spectroscopy literature in anorexia nervosa is reviewed and we outline the brain region-specific neurometabolite changes that have been reported and their connection to anorexia nervosa psychopathology. Considering the proposed role of dysfunctional neurotransmission in anorexia nervosa, the potential utility of zinc supplementation and sub-anaesthetic doses of ketamine in normalising this is discussed with reference to previous research in anorexia nervosa and other neuropsychiatric conditions. The rationale for future research to investigate the combined use of low-dose ketamine and zinc supplementation to potentially extend the therapeutic benefits in anorexia nervosa is subsequently explored and promising biological markers for assessing and potentially predicting treatment response are outlined.

Psychedelic-Assisted Therapy for People with Eating Disorders

PURPOSE OF REVIEW

A growing body of research suggests psychedelic-assisted therapy (PAT) may be safe and effective for a variety of mental health conditions. Among these, eating disorders have been a recent target of interest. This review provides an up-to-date summary of the potential mechanisms and use of PAT in people diagnosed with eating disorders, with a focus on anorexia nervosa.

RECENT FINDINGS

Classic psychedelics may have transdiagnostic efficacy through several mechanisms relevant to eating disorder pathology. Interest in, and efforts to increase access to PAT are both high. Early clinical trials are focused on establishing the safety and utility of this treatment in eating disorders, and efficacy remains unclear. High-quality published data to support the use of PAT for people with eating disorders remains lacking. Recent studies however suggest PAT has the potential to augment the efficacy of current interventions for these difficult-to-treat conditions.

A century of research on psychedelics: A scientometric analysis on trends and knowledge maps of hallucinogens, entactogens, entheogens and dissociative drugs

A scientometric analysis was realized to outline clinical research on psychedelics over the last century. Web of Science Core Collection was searched up to March 18, 2022, for publications on psychedelics. Network analyses and bibliometrics were combined, to identify research themes and trends with Bibliometrix and CiteSpace. The primary aim was to measure research trends evolution over time, and the secondary aims were to identify bibliometric performance and influence networks of publications, authors, institutions, and countries. Sensitivity analyses were conducted for 2016-2022, and 2021 time periods. We included 31,687 documents (591,329 references), which aggregated into a well-structured network with credible clustering. Research productivity was split into an early less productive period mainly focusing on safety issues, and a "psychedelic renaissance" after the 1990s. Major trends were identified for hallucinogens/entheogens, entactogens, novel psychoactive substances (NPS), and on dissociative substances. There was a translational evolution from the bench to the bedside, with phase 2 and 3 trials and/or evidence synthesis in particular. The most recent trends concerned NPS, ketamine-associated brain changes, and ayahuasca-assisted psychotherapy. The USA and Canada were the most productive settings for the research overall, and more recently this geographical distribution became more prominent, reflecting legislative context/policy making. A translational evolution of psychedelics has been occurring, that has brought approval of esketamine for depression and will likely lead to approval of additional psychedelics across mental and physical conditions. Toxicology screening tools for NPS are urgently needed, which in turn might follow the same translational evolution of psychedelics in the future.

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.

Immunoinflammatory processes: Overlapping mechanisms between obesity and eating disorders?

Obesity and eating disorders are conditions that involve eating behaviors and are sometimes comorbid. Current evidence supports alterations in immunoinflammatory processes in both obesity and eating disorders. A plausible hypothesis is that immunoinflammatory processes may be involved in the pathophysiology of obesity and eating disorders. The aim of this review is to highlight the link between obesity and eating disorders, with a particular focus on immunoinflammatory processes. First, the relation between obesity and eating disorders will be presented, followed by a brief review of the literature on their association with immunoinflammatory processes. Second, developmental factors will be discussed to clarify the link between obesity, eating disorders, and immunoinflammatory processes. Genetic and epigenetic risk factors as well as the potential roles of stress pathways and early life development will be presented. Finally, implications of these findings for future research are discussed. This review highlighted biological and developmental aspects that overlap between obesity and EDs, emphasizing the need for biopsychosocial research approaches to advance current knowledge and practice in these fields.

Not just an upset stomach: gastric perforation in a patient with anorexia nervosa

Gastric perforation in patients with anorexia nervosa is a rare entity associated with high morbidity and mortality [Norris in Int J Eat Disord 49:216-237, 2016]. In cases reported in the literature, the perforation was often preceded by a binge episode, and the subsequent clinical presentation was rapid and acutely deteriorating with a fatality rate as high as 80% [Norris in Int J Eat Disord 49:216-237, 2016, Pitre in J Med Case Rep 15:61, 2021]. We present a case of gastric perforation in the context of restrictive anorexia nervosa unique both for the absence of a premorbid binge episode as well as delayed clinical manifestations of medical distress, leading to abdominal compartment syndrome.Level IV Evidence obtained from multiple time series analysis such as case studies.

Short communication: Serum levels of brain-derived neurotrophic factor and association with pro-inflammatory cytokines in acute and recovered anorexia nervosa

Brain-derived neurotrophic factor (BDNF) is a neuroprotective molecule known to be involved in neuroplasticity, learning and memory. Additionally, it may mitigate the effects of inflammation on the brain. There is inconclusive evidence as to whether reductions in BDNF found in AN are related to features associated with the illness such as changes in inflammatory markers and comorbidities, and whether they persist after recovery. This cross-sectional study measured BDNF and 36 inflammatory markers in the serum of individuals recovered from AN (rec-AN; n = 24), with acute AN (n = 56), and healthy controls (n = 51). We (a) compared BDNF concentrations between AN, rec-AN and controls including four pre-determined covariates; (b) assessed the relationship between BDNF and body mass index, eating disorder (ED) psychopathology and depression; and (c) correlated BDNF with inflammatory markers, stratified by group. The AN group showed reductions in BDNF compared to controls and rec-AN. BDNF was negatively associated with depression and ED psychopathology in the whole sample, but not the AN sample. BDNF was positively correlated with three inflammatory markers in the control group (interleukin (IL)-8, Eotaxin-3, tumor necrosis factor (TNF)-α) and negatively correlated with one (IL-16). The only pro-inflammatory marker associated with BDNF in the AN group was TNF-α, and no pro-inflammatory markers were associated with BDNF in the rec-AN group. These results indicate that BDNF serum concentrations may be a state marker of AN. In people with acute AN, BDNF levels seem to be linked to TNF-α signalling. However, BDNF concentrations do not appear to reflect AN symptom severity.

In pursuit of biomarkers for predicting susceptibility to activity-based anorexia in adolescent female rats

OBJECTIVE

Identifying risk factors that contribute to the development of anorexia nervosa (AN) is critical for the implementation of early intervention strategies. Anxiety, obsessive-compulsive behavior, and immune dysfunction may be involved in the development of AN; however, their direct influence on susceptibility to the condition remains unclear. Here, we used the activity-based anorexia (ABA) model to examine whether activity, anxiety-like behavior, compulsive behavior, and circulating immune markers predict the subsequent development of pathological weight loss.

METHOD

Female Sprague-Dawley rats (n = 44) underwent behavioral testing before exposure to ABA conditions after which they were separated into susceptible and resistant subpopulations. Blood was sampled before behavioral testing and after recovery from ABA to screen for proinflammatory cytokines.

RESULTS

Rats that were vulnerable to pathological weight loss differed significantly from resistant rats on all key ABA parameters. While the primary measures of anxiety-like or compulsive behavior were not shown to predict vulnerability to ABA, increased locomotion and anxiety-like behavior were both associated with the extent of weight loss in susceptible but not resistant animals. Moreover, the change in expression of proinflammatory markers IL-4 and IL-6 evoked by ABA was associated with discrete vulnerability factors. Intriguingly, behavior related to risk assessment was shown to predict vulnerability to ABA.

DISCUSSION

We did not find undisputable behavioral or immune predictors of susceptibility to pathological weight loss in the ABA rat model. Future research should examine the role of cognition in the development of ABA, dysfunction of which may represent an endophenotype linking anorectic, anxiety-like and compulsive behavior.

PUBLIC SIGNIFICANCE

Anorexia nervosa (AN) has among the highest mortality rates of all psychiatric disorders and treatment options remain limited in their efficacy. Understanding what types of risk factors contribute to the development of AN is essential for implementing early intervention strategies. This study describes how some of the most common psychological features of AN could be used to predict susceptibility to pathological weight loss in a well-established animal model.

Genetic estimates of correlation and causality between blood-based biomarkers and psychiatric disorders

There is a long-standing interest in exploring the relationship between blood-based biomarkers and psychiatric disorders, despite their causal role being difficult to resolve in observational studies. In this study, we leverage genome-wide association study data for a large panel of heritable serum biochemical traits to refine our understanding of causal effect in biochemical-psychiatric trait pairings. We observed widespread positive and negative genetic correlation between psychiatric disorders and biochemical traits. Causal inference was then implemented to distinguish causation from correlation, with strong evidence that C-reactive protein (CRP) exerts a causal effect on psychiatric disorders. Notably, CRP demonstrated both protective and risk-increasing effects on different disorders. Multivariable models that conditioned CRP effects on interleukin-6 signaling and body mass index supported that the CRP-schizophrenia relationship was not driven by these factors. Collectively, these data suggest that there are shared pathways that influence both biochemical traits and psychiatric illness.

Low levels of proinflammatory cytokines in a transdiagnostic sample of young male and female early onset eating disorders without any previous treatment: A case control study

Growing interest exists in the association of the immune system and its role in the development and maintenance of eating disorders (ED). Current evidence suggests that serum cytokine levels seem to be elevated in females with anorexia nervosa (AN). However, less is known in bulimia nervosa (BN) and other specified feeding and eating disorders (OSFED), specially in males. We aimed to perform a case-control study in a sample of forty eight young patients (38 females and 10 males) with early diagnosis of AN, BN or OSFED and without any previous treatment, compared with twenty nine healthy controls (19 females and 10 males) matched by age, sex and socioeconomic status. We evaluated eating-related psychopathology and depressive symptoms and measured serum concentration of proinflammatory cytokines IL-1β, IL-6, and TNF-α and anti-inflammatory cytokine IL-10. Contrary to expectations, levels of IL-1β and IL-6 were significantly lower in ED patients, compared with healthy controls. Comparing the different groups of females, we found elevated levels of IL-10 among ED patients therefore supporting the idea of an immunosuppressive status in the early stages. This could indicate that early onset patients without any previous treatment could remain in a reward-dependent state with a lower immune response.

White matter integrity is disrupted in adolescents with acute anorexia nervosa: A diffusion tensor imaging study

Anorexia nervosa (AN) is a highly debilitating mental illness with multifactorial etiology. It oftentimes begins in adolescence, therefore understanding the pathophysiology in this period is important. Few studies investigated the possible impact of the acute state of illness on white matter (WM) tissue properties in the developing adolescent brain. The present study expands our understanding of the implications of AN and starvation on WM integrity. 67 acutely ill adolescent patients suffering from AN restricting type were compared with 32 healthy controls using diffusion tensor imaging assessing fractional anisotropy (FA) and mean diffusivity (MD). We found widespread alterations in the vast majority of the WM regions with significantly decreased FA and increased MD in the AN group. In this highly selective sample in the acute stage of AN, the alterations are likely to be the consequence of starvation. Still, we cannot rule out that some of the affected regions might play a key role in AN-specific psychopathology.

Effect and Mechanism of Herbal Medicines on Cisplatin-Induced Anorexia

Cisplatin is a well-known chemotherapeutic agent used to treat various types of cancers; however, it can also induce anorexia, which results in reduced food intake, loss of body weight, and lower quality of life. Although drugs such as megestrol acetate and cyproheptadine are used to decrease this severe feeding disorder, they can also induce side effects, such as diarrhea and somnolence, which limit their widespread use. Various types of herbal medicines have long been used to prevent and treat numerous gastrointestinal tract diseases; however, to date, no study has been conducted to analyze and summarize their effects on cisplatin-induced anorexia. In this paper, we analyze 12 animal studies that used either a single herbal medicine extract or mixtures thereof to decrease cisplatin-induced anorexia. Among the herbal medicines, Ginseng Radix was the most used, as it was included in seven studies, whereas both Glycyrrhizae Radix et Rhizoma and Angelicae Gigantis Radix were used in four studies. As for the mechanisms of action, the roles of serotonin and its receptors, cytokines, white blood cells, ghrelin, and leptin were investigated. Based on these results, we suggest that herbal medicines could be considered a useful treatment method for cisplatin-induced anorexia.

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.

Expression of CXCR4 on CD4+ T cells predicts body composition parameters in female adolescents with anorexia nervosa

Anorexia nervosa (AN) is a severe eating disorder characterized by excessive weight loss and lack of recognition of the seriousness of the current low body weight. Individuals with AN frequently exhibit an enhanced inflammatory state and altered blood levels of cytokines and chemokines. However, the expression of chemokine receptors in AN and the association with body composition parameters and treatment effects are still unknown. In this study, we examined the expression of CCR4, CCR6, CXCR3, and CXCR4 on peripheral blood T cells in female adolescents with AN before (T0, n = 24) and after 6 weeks of multimodal therapy (T1, n = 20). We also investigated their value to predict body mass index (BMI) and fat mass index (FMI) at baseline. Using multi-parameter flow cytometry, we found increased expression of CCR4, CXCR3, and CXCR4, but not CCR6, on CD4⁺ T cells in AN at T0 when compared to healthy controls (HC, n = 20). At T1, CXCR3 and CXCR4 expression decreased in AN. We found a close link between CCR4, CCR6 and CXCR4 expression and the adolescent mental health status in the study cohort as determined by the Strengths and Difficulties Questionnaire (SDQ). Specifically, CXCR4 expression correlated positively with emotional symptoms and peer relationship problems, as well as with the total sum score of the SDQ. In addition, CXCR4 expression on CD4⁺ T cells was a significant predictor of BMI and FMI in female adolescents. Our findings that CXCR4 expression on T cells is altered in adolescents with AN and predicts body composition parameters in adolescents suggest an impact of this chemokine receptor in the pathogenesis of AN.

Brick by Brick: Building a Transdiagnostic Understanding of Inflammation in Psychiatry

ABSTRACT

Inflammatory phenomena are found in many psychiatric disorders-notably, depression, schizophrenia, and posttraumatic stress disorder. Inflammation has been linked to severity and treatment resistance, and may both contribute to, and result from, the pathophysiology of some psychiatric illnesses. Emerging research suggests that inflammation may contribute to symptom domains of reward, motor processing, and threat reactivity across different psychiatric diagnoses. Reward-processing deficits contribute to motivational impairments in depression and schizophrenia, and motor-processing deficits contribute to psychomotor slowing in both depression and schizophrenia. A number of experimental models and clinical trials suggest that inflammation produces deficits in reward and motor processing through common pathways connecting the cortex and the striatum, which includes the nucleus accumbens, caudate nucleus, and putamen.The observed effects of inflammation on psychiatric disorders may cut across traditional conceptualizations of psychiatric diagnoses. Further study may lead to targeted immunomodulating treatments that address difficult-to-treat symptoms in a number of psychiatric disorders. In this review, we use a Research Domain Criteria framework to discuss proposed mechanisms for inflammation and its effects on the domains of reward processing, psychomotor slowing, and threat reactivity. We also discuss data that support contributing roles of metabolic dysregulation and sex differences on the behavioral outcomes of inflammation. Finally, we discuss ways that future studies can help disentangle this complex topic to yield fruitful results that will help advance the field of psychoneuroimmunology.

Systemic inflammatory biomarkers in DSM-5 defined disorders and COVID-19: Evidence from published meta-analyses

On March 11, 2020, the World Health Organization declared the outbreak of the novel SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) as a global pandemic. At the center of SARS-CoV-2 is the activation of inflammatory markers; remarkably, interleukin 6 and C-reactive protein seem to be consistently elevated in patients with SARS-CoV-2. Here, we showed that increased systemic C-reactive protein and interleukin 6 are common biomarkers of both severe COVID-19 and DSM-5-defined disorders. However, it is not known whether patients with psychiatric disorders with preexisting increased interleukin 6 and C-reactive protein are more vulnerable to severe complications of COVID-19 because of the additive inflammatory processes.

Lower serum levels of IL-1β and IL-6 cytokines in adolescents with anorexia nervosa and their association with gut microbiota in a longitudinal study

INTRODUCTION

Anorexia nervosa (AN) is an often chronic and debilitating psychiatric disease whose etiology is not completely understood. Recently, a potential role of inflammation has emerged in other psychiatric diseases, such as depression, PTSD and schizophrenia. The first results in adults with AN seemed to confirm a low-grade proinflammatory state until recent studies presented more differential findings. Studying adolescents with a shorter illness duration and fewer confounding factors might help elucidate the role of inflammation in the underlying pathophysiology of AN; however, the few available studies in adolescents remain ambiguous, and no longitudinal data are available in this age range.

METHODS

We examined the proinflammatory cytokines Tumor Necrosis Factor-alpha (TNF-α), Interleukin (IL)-1β, IL-6, IL-15, and the cytokine-receptor IL-6 Receptor alpha (IL-6 Rα) in the serum of twenty-two hospitalized female adolescent patients with AN longitudinally at admission and discharge and compared their results to nineteen healthy controls (HC). We also collected clinical data and stool samples that were analyzed with 16S rRNA amplicon sequencing to explore potential influencing factors of cytokine changes.

RESULTS

TNF-α serum levels were significantly elevated in patients with AN at admission, while IL-1β and IL-6 levels were lower at admission and discharge than in HC. After treatment, we also found significantly elevated levels of IL-6 Rα compared to HC, while IL-15 did not show significant changes. Exploratory analyses revealed positive associations of cytokine and genus-level changes between admission and discharge for IL-1β (Bacteroides) and IL-15 (Romboutsia), and negative associations for IL-15 (Anaerostipes) and TNF-α (uncultured Lachnospiraceae).

CONCLUSION

We confirmed a previous finding of elevated levels of TNF-α also in adolescents with AN; however, the reduced IL-1β and IL-6 levels differed from the mostly increased levels found in adults. A mixed pro- and anti-inflammatory state appears to be present in adolescents, potentially due to their shorter illness duration. The gut microbiota, with its regulatory function on cytokine production, might play a role in mediating these inflammatory processes in AN and could offer targets for new therapeutic approaches.

Brain Volume Loss, Astrocyte Reduction, and Inflammation in Anorexia Nervosa

Anorexia nervosa is the third most common chronic disease in adolescence and is characterized by low body weight, body image distortion, weight phobia, and severe somatic consequences. Among the latter, marked brain volume reduction has been linked to astrocyte cell count reduction of about 50% in gray and white matter, while neuronal and other glial cell counts remain normal. Exact underlying mechanisms remain elusive; however, first results point to important roles of the catabolic state and the very low gonadal steroid hormones in these patients. They also appear to involve inflammatory states of "hungry astrocytes" and interactions with the gut microbiota. Functional impairments could affect the role of astrocytes in supporting neurons metabolically, neurotransmitter reuptake, and synapse formation, among others. These could be implicated in reduced learning, mood alterations, and sleep disturbances often seen in patients with AN and help explain their rigidity and difficulties in relearning processes in psychotherapy during starvation.

Nutrient Intake and Dietary Inflammatory Potential in Current and Recovered Anorexia Nervosa

Anorexia nervosa (AN) is characterised by disrupted and restrictive eating patterns. Recent investigations and meta-analyses have found altered concentrations of inflammatory markers in people with current AN. We aimed to assess nutrient intake in participants with current or recovered AN, as compared to healthy individuals, and explore group differences in dietary inflammatory potential as a possible explanation for the observed alterations in inflammatory markers. We recruited participants with current AN (n = 51), those recovered from AN (n = 23), and healthy controls (n = 49). We used the Food Frequency Questionnaire (FFQ), to calculate a Dietary Inflammatory Index (DII^®) score and collected blood samples to measure serum concentrations of inflammatory markers. In current AN participants, we found lower intake of cholesterol, compared to HCs, and lower consumption of zinc and protein, compared to HC and recovered AN participants. A one-way ANOVA revealed no significant group differences in DII score. Multivariable regression analyses showed that DII scores were significantly associated with tumour necrosis factor (TNF)-α concentrations in our current AN sample. Our findings on nutrient intake are partially consistent with previous research. The lack of group differences in DII score, perhaps suggests that diet is not a key contributor to altered inflammatory marker concentrations in current and recovered AN. Future research would benefit from including larger samples and using multiple 24-h dietary recalls to assess dietary intake.

Ketamine as a Treatment for Anorexia Nervosa: A Narrative Review

Anorexia nervosa (AN) is a highly complex disorder to treat, especially in severe and enduring cases. Whilst the precise aetiology of the disorder is uncertain, malnutrition and weight loss can contribute to reductions in grey and white matter of the brain, impairments in neuroplasticity and neurogenesis and difficulties with cognitive flexibility, memory and learning. Depression is highly comorbid in AN and may be a barrier to recovery. However, traditional antidepressants are often ineffective in alleviating depressive symptoms in underweight patients with AN. There is an urgent need for new treatment approaches for AN. This review gives a conceptual overview for the treatment of AN with ketamine. Ketamine has rapid antidepressant effects, which are hypothesised to occur via increases in glutamate, with sequelae including increased neuroplasticity, neurogenesis and synaptogenesis. This article provides an overview of the use of ketamine for common psychiatric comorbidities of AN and discusses particular safety concerns and side effects. Potential avenues for future research and specific methodological considerations are explored. Overall, there appears to be ample theoretical background, via several potential mechanisms, that warrant the exploration of ketamine as a treatment for adults with AN.