Coexistence of eating disorders and autoimmune diseases: Record linkage cohort study, UK

Risk of self-harm in patients with eating disorders: English population-based national record-linkage study, 1999-2021

OBJECTIVE

Anorexia nervosa (AN) and bulimia nervosa (BN) are eating disorders associated with high rates of self-harm (SH). This is the first national study in England to quantify this association in a hospital population.

METHOD

A retrospective cohort study using a linked national dataset of Hospital Episode Statistics for 1999-2021. The exposure cohort included individuals aged <35 years admitted to hospital with a diagnosis of AN or BN. The reference cohort included hospital controls. We calculated the rate ratio (RR) of SH in each cohort. The individuals in the two cohorts were matched on multiple socio-demographic indicators. The main outcome was a subsequent hospitalization or death record with an SH diagnosis.

RESULTS

We identified 15,004 females and 1411 males with AN, and 6055 females and 741 males with BN. The RR with 95% confidence intervals (95%CI) for a subsequent admission with intentional self-harm after admission with AN was 4.9 (95%CI 4.7-5.1) in females and 4.8 (95%CI 3.9-5.8) in males. For BN it was 9.0 (95%CI 8.4-9.6) in females and 9.8 (95%CI 7.7-12.2) in males. There were strong associations between AN and BN and other SH.

DISCUSSION

Women and men admitted to English hospitals with AN or BN have a very high risk of a subsequent admission with SH. For some SH behaviors, such as alcohol intoxication, the RR was >10-fold elevated. The magnitude of risk was higher for BN than for AN. Clinicians should be aware of the scale of risk increase. Providing those at risk with appropriate support is required.

PUBLIC SIGNIFICANCE

This study is the first national study in an English hospital population that confirms and quantifies the association between eating disorders and self-harm. We have found that both women and men admitted to hospital with anorexia nervosa or bulimia nervosa are at an increased risk of subsequent admission with self-harm. It is important that clinicians are aware of this increased risk to support those at highest risk of self-harm.

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.

Prevalence and Multidimensional Model of Disordered Eating in Youths With Type 1 Diabetes: Results From a Nationwide Population-Based Study

OBJECTIVE

The aim of this study was to report nationwide data of the prevalence of disordered eating behaviors (DEBs) in adolescents with type 1 diabetes (T1D) and to evaluate a multidimensional model of eating problems, analyzing how psychopathological problems are associated with DEBs and with metabolic control.

METHODS

This study was carried out using a cross-sectional design with a sample of 1,562 patients with T1D (812 male), aged 11-19 years. Participants were recruited from multiple pediatric diabetes centers (N = 30) located in northern, central, and southern Italy, and they individually completed the Diabetes Eating Problem Survey-Revised (DEPS-r) and the Youth Self-Report (YSR). Sociodemographic and clinical data were also gathered. Multiple-group structural equation modeling was used to investigate the relationships between internalizing/externalizing symptoms, DEBs, and glycosylated hemoglobin (HbA1c) values.

RESULTS

A total of 29.7% of the participants reported DEBs (DEPS-r scores ≥20), 42.4% reported insulin manipulation (IM). The prevalence of DEBs was higher for female participants (p ≤ .001). The model explains 37% of the variance in disordered eating, 12% in IM, and 21% in HbA1c values. Body mass index, externalizing symptoms, and internalizing symptoms were significantly and positively associated with DEBs, which in turn were significantly and positively associated with HbA1c values (all p ≤ .001). Externalizing (p ≤ .001) and internalizing (p ≤ .01) symptoms were also directly associated with HbA1c values.

CONCLUSION

Given the relevant prevalence of DEBs, their significant positive association with psychopathological symptoms, and their relationship with worse diabetes outcomes, regular psychological screening and support is needed to ensure the best care of adolescents with T1D.

Low risk of some common cancers in women with anorexia nervosa: Evidence from a national record-linkage study

BACKGROUND

Some studies report that women with anorexia nervosa (AN) have lower risk than others of breast cancer, but increased risk of cancers of other sites. No work has been done to quantify the risk in the English population.

METHODS

Retrospective cohort study using a national linked dataset of Hospital Episode Statistics for 1999-2021. We selected individuals with a hospital admission for AN, and compared their relative risk (RR) of developing site-specific cancers, with that in a reference cohort.

RESULTS

We identified 75 cancers in 15,029 women hospitalised with AN. There was a low RR of all cancers combined at 0.75 (95%CI 0.59-0.94), and, notably, low RR for breast cancer 0.43 (0.20-0.81), cancers of secondary and ill-defined sites 0.52 (0.26-0.93). The RR for parotid gland cancer was 4.4 (1.4-10.6) within a year of first recorded diagnosis of AN. In men, we found 12 cancers in 1413 individuals hospitalised with AN, but no increased risks beyond the first year of diagnosis of AN.

CONCLUSIONS

This is the first report on the association between AN and cancers in the all-England population. The study showed low rates of breast cancer, and of all cancers combined, in women hospitalised with AN. It is possible that some of the metabolic or hormonal changes observed in AN could work as a protective factor for breast cancer. More experimental work is needed to identify and explain these factors. The new finding on the higher risk of salivary gland tumours could inform clinicians caring for patients with AN.

Psychiatric and medical comorbidities of eating disorders: findings from a rapid review of the literature

BACKGROUND

Eating disorders (EDs) are potentially severe, complex, and life-threatening illnesses. The mortality rate of EDs is significantly elevated compared to other psychiatric conditions, primarily due to medical complications and suicide. The current rapid review aimed to summarise the literature and identify gaps in knowledge relating to any psychiatric and medical comorbidities of eating disorders.

METHODS

This paper forms part of a rapid review) series scoping the evidence base for the field of EDs, conducted to inform the Australian National Eating Disorders Research and Translation Strategy 2021-2031, funded and released by the Australian Government. ScienceDirect, PubMed and Ovid/Medline were searched for English-language studies focused on the psychiatric and medical comorbidities of EDs, published between 2009 and 2021. High-level evidence such as meta-analyses, large population studies and Randomised Control Trials were prioritised.

RESULTS

A total of 202 studies were included in this review, with 58% pertaining to psychiatric comorbidities and 42% to medical comorbidities. For EDs in general, the most prevalent psychiatric comorbidities were anxiety (up to 62%), mood (up to 54%) and substance use and post-traumatic stress disorders (similar comorbidity rates up to 27%). The review also noted associations between specific EDs and non-suicidal self-injury, personality disorders, and neurodevelopmental disorders. EDs were complicated by medical comorbidities across the neuroendocrine, skeletal, nutritional, gastrointestinal, dental, and reproductive systems. Medical comorbidities can precede, occur alongside or emerge as a complication of the ED.

CONCLUSIONS

This review provides a thorough overview of the comorbid psychiatric and medical conditions co-occurring with EDs. High psychiatric and medical comorbidity rates were observed in people with EDs, with comorbidities contributing to increased ED symptom severity, maintenance of some ED behaviours, and poorer functioning as well as treatment outcomes. Early identification and management of psychiatric and medical comorbidities in people with an ED may improve response to treatment and overall outcomes.

Risk Factors from Pregnancy to Adulthood in Multiple Sclerosis Outcome

Multiple sclerosis (MS) is an autoimmune disease characterized by a robust inflammatory response against myelin sheath antigens, which causes astrocyte and microglial activation and demyelination of the central nervous system (CNS). Multiple genetic predispositions and environmental factors are known to influence the immune response in autoimmune diseases, such as MS, and in the experimental autoimmune encephalomyelitis (EAE) model. Although the predisposition to suffer from MS seems to be a multifactorial process, a highly sensitive period is pregnancy due to factors that alter the development and differentiation of the CNS and the immune system, which increases the offspring’s susceptibility to develop MS. In this regard, there is evidence that thyroid hormone deficiency during gestation, such as hypothyroidism or hypothyroxinemia, may increase susceptibility to autoimmune diseases such as MS. In this review, we discuss the relevance of the gestational period for the development of MS in adulthood.

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.

Esophageal achalasia diagnosed in people previously diagnosed with an eating disorder: Epidemiological study using record-linkage

OBJECTIVE

Occasionally, patients with eating disorders have been subsequently diagnosed with esophageal achalasia. We sought to establish whether eating disorders and achalasia coexisted more often than expected by chance alone.

METHOD

National record-linkage study of hospital inpatients in England, between 2001 and 2017. Use of Cox proportional hazards to compare the occurrence of achalasia in cohorts of people with or without anorexia nervosa (AN), and with or without bulimia nervosa (BN), with adjustment of the comparisons for such confounders as age, sex, and year of admission.

RESULTS

There were 18,500 people in the AN cohort, 11,300 in the BN cohort, and 8.7 million in the comparison cohort. The Cox regression hazard ratio, comparing the AN cohort with the reference cohort, was 3.4 (95% confidence interval 1.8-6.3) and that in the BN cohort was 4.2 (2.2-8.2).

DISCUSSION

AN and achalasia, and BN and achalasia, were diagnosed in the same individuals, more often than expected by chance. Clinicians should be aware of the possible associations with achalasia because the treatment of eating disorders and achalasia is different.

Emerging Comorbidities in Inflammatory Bowel Disease: Eating Disorders, Alcohol and Narcotics Misuse

Inflammatory bowel disease (IBD) is a chronic and potentially devastating condition of the digestive tract which is exemplified by increasing prevalence worldwide, byzantine pathogenesis with a poorly defined role of the environmental factors, and complex clinical demonstration. As a systemic disease, IBD may progress with a wide spectrum of extraintestinal manifestations (EMs) and comorbidities affecting different organs and systems, from anaemia, undernutrition, and cancer to those which are often neglected like anxiety and depression. Evolving IBD epidemiology and changing environment are reflected by an expanding list of IBD-related comorbidities. In contrast to the well-established role of smoking the connection between alcohol and IBD is still debatable on many levels, from pathogenesis to complications. Furthermore, little is known about narcotics use in IBD patients, even if there are obvious factors that may predispose them to narcotics as well as alcohol misuse. Last but not least, the question arises what is the prevalence of eating disorders in IBD. In our paper, we aimed to discuss the current knowledge on alcohol and drugs misuse and eating disorders as emerging extraintestinal comorbidities in IBD.

A systematic review and meta-analysis of the prevalence and odds of eating disorders in patients with celiac disease and vice-versa

OBJECTIVES

In the present systematic review and meta-analysis study, we aimed to review studies that assessed the prevalence and risk of eating disorders (EDs) in patients with celiac disease (CD) and vice-versa.

METHOD

We conducted a systematic search in PubMed, Embase, Scopus, and Web of Science for studies that assessed the prevalence and risk of AN in patients with CD and vice-versa. Joanna Briggs Institute tools were used for critical appraisal. The STATA software was used for the meta-analysis of the random-effect model.

RESULTS

In this study, 23 observational studies were included. The results of the meta-analysis indicated that the pooled prevalence of EDs and bulimia nervosa in patients with CD was 8.88% [95% CI: 6.4, 11.7] and 7.26% [95% CI: 0.23, 21.57], respectively. Moreover, the risk of anorexia nervosa in patients with CD was significantly higher than in the healthy population (relative risk [RR]: 1.48 [95% CI: 1.32, 1.64]). The rates of CD in patients with AN and EDs were 0.96% [95% CI: 0.15, 2.31] and 0.90% [95% CI: 0.56, 1.31], respectively. Moreover, the overall risk of CD in patients with AN was significantly higher compared with healthy adults (RR: 2.35 [95% CI: 1.27-3.44]).

DISCUSSION

The result of the present meta-analysis showed the high prevalence of EDs in patients with CD. Moreover, there was a significant bidirectional association between CD and EDs.

The intersect of gastrointestinal symptoms and malnutrition associated with anorexia nervosa and avoidant/restrictive food intake disorder: Functional or pathophysiologic?-A systematic review

OBJECTIVE

Although multiple pathophysiologic changes develop within the gastrointestinal (GI) system in the setting of malnutrition, the etiology of the reported multitude of symptoms in those with anorexia nervosa and avoidant restrictive intake disorder, as well as their contribution toward disordered eating, remain poorly understood. This systematic review seeks to better understand how these physiologic changes of malnutrition of the esophagus, stomach, intestines, and pancreas contribute toward the reported GI symptoms, as well as better understand how celiac disease, inflammatory bowel disease, pelvic floor dysfunction, and Ehlers-Danlos syndrome contribute toward disordered eating.

METHODS

Studies of any design exploring the pathogenesis of complications and treatment strategies were included. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were used to structure and complete the review.

RESULTS

A total of 146 articles were used for the review. The majority of studies were observational or case reports/case series.

DISCUSSION

Pathophysiologic changes of the esophagus, stomach, and intestines develop with malnutrition, although these changes do not consistently correlate with expressed GI symptoms in patients with restrictive eating disorders. Celiac disease and inflammatory bowel disease also contribute to disordered eating through the associated somatic GI complaints, while pelvic floor dysfunction and Ehlers-Danlos syndrome contribute through both somatic symptoms and functional symptoms. Indeed, functional GI symptoms remain problematic during the course of treatment, and further research is required to better understand the extent to which these symptoms are functional in nature and remit or remain as treatment ensues.

Alterations in B cell subsets correlate with body composition parameters in female adolescents with anorexia nervosa

Anorexia nervosa (AN) is a severe eating disorder and often associated with altered humoral immune responses. However, distinct B cell maturation stages in peripheral blood in adolescents with AN have not been characterized. Treatment effects and the relationship between clinical and B cell parameters are also not fully understood. Here we investigated the phenotype of circulating B cell subsets and the relationship with body composition in adolescents with AN before (T0, n = 24) and after 6 weeks (T1, n = 20) of treatment. Using multi-parameter flow cytometry, we found increased percentages of antigen-experienced B cells and plasmablasts in patients with AN compared to healthy controls (n = 20). In contrast, percentages of CD1d⁺CD5⁺ B cells and transitional B cells with immunoregulatory roles were reduced at T0 and T1. These B cell frequencies correlated positively with fat mass, fat mass index (FMI), free fat mass index, and body mass index standard deviation score. In addition, scavenger-like receptor CD5 expression levels were downregulated on transitional B cells and correlated with fat mass and FMI in AN. Our findings that regulatory B cell subgroups were reduced in AN and their strong relationship with body composition parameters point toward an impact of immunoregulatory B cells in the pathogenesis of AN.

Association of Primary Humoral Immunodeficiencies With Psychiatric Disorders and Suicidal Behavior and the Role of Autoimmune Diseases

IMPORTANCE

The hypothesis that disrupted immune function is implicated in the pathophysiology of psychiatric disorders and suicide is gaining traction, but the underlying mechanisms are largely unknown. Primary humoral immunodeficiencies (PIDs) are rare deficiencies of the immune system-mainly dysfunction of antibody production-and are associated with adverse health problems, such as recurrent infections and autoimmune diseases.

OBJECTIVE

To establish whether PIDs that affect antibody function and level are associated with lifetime psychiatric disorders and suicidal behavior and whether this association is explained by the co-occurrence of autoimmune diseases.

DESIGN, SETTING, AND PARTICIPANTS

This population- and sibling-based cohort study included more than 14 million individuals living in Sweden from January 1, 1973, through December 31, 2013. Register-based data on exposure, outcomes, and covariates were collected through December 31, 2013. Individuals with a record of PID were linked to their full siblings, and a family identification number was created. Data were analyzed from May 17, 2019, to February 21, 2020.

EXPOSURES

Lifetime records of PID and autoimmune disease.

MAIN OUTCOMES AND MEASURES

Lifetime records of 12 major psychiatric disorders and suicidal behavior, including suicide attempts and death by suicide.

RESULTS

A lifetime diagnosis of PID affecting immunoglobulin levels was identified in 8378 patients (4947 women [59.0%]; median age at first diagnosis, 47.8 [interquartile range, 23.8-63.4] years). A total of 4776 clusters of full siblings discordant for PID was identified. After adjusting for comorbid autoimmune diseases, PIDs were associated with greater odds of any psychiatric disorder (adjusted odds ratio [AOR], 1.91; 95% CI, 1.81-2.01) and any suicidal behavior (AOR, 1.84; 95% CI, 1.66-2.04). The associations were also significant for all individual psychiatric disorders (range of AORs, 1.34 [95% CI, 1.17-1.54] for schizophrenia and other psychotic disorders to 2.99 [95% CI, 2.42-3.70] for autism spectrum disorders), death by suicide (AOR, 1.84; 95% CI, 1.25-2.71), and suicide attempts (AOR, 1.84; 95% CI, 1.66-2.04). In the sibling comparisons, the associations were attenuated but remained significant for aggregated outcomes (AOR for any psychiatric disorder, 1.64 [95% CI, 1.48-1.83]; AOR for any suicidal behavior, 1.37 [95% CI, 1.14-1.66]), most individual disorders (range of AORs, 1.46 [95% CI, 1.23-1.73] for substance use disorders to 2.29 [95% CI, 1.43-3.66] for autism spectrum disorders), and suicide attempts (AOR, 1.41; 95% CI, 1.17-1.71). Joint exposure for PID and autoimmune disease resulted in the highest odds for any psychiatric disorder (AOR, 2.77; 95% CI, 2.52-3.05) and any suicidal behavior (AOR, 2.75; 95% CI, 2.32-3.27). The associations with psychiatric outcomes (AORs, 2.42 [95% CI, 2.24-2.63] vs 1.65 [95% CI, 1.48-1.84]) and suicidal behavior (AORs, 2.43 [95% CI, 2.09-2.82] vs 1.40 [95% CI, 1.12-1.76]) were significantly stronger for women than for men with PID.

CONCLUSIONS AND RELEVANCE

Primary humoral immunodeficiencies were robustly associated with psychopathology and suicidal behavior, particularly in women. The associations could not be fully explained by co-occurring autoimmune diseases, suggesting that antibody dysfunction may play a role, although other mechanisms are possible. Individuals with both PID and autoimmune disease had the highest risk of psychiatric disorders and suicide, suggesting an additive effect. Future studies should explore the underlying mechanisms of these associations.

Study protocol of comprehensive risk evaluation for anorexia nervosa in twins (CREAT): a study of discordant monozygotic twins with anorexia nervosa

BACKGROUND

Anorexia nervosa (AN) is a severe disorder, for which genetic evidence suggests psychiatric as well as metabolic origins. AN has high somatic and psychiatric comorbidities, broad impact on quality of life, and elevated mortality. Risk factor studies of AN have focused on differences between acutely ill and recovered individuals. Such comparisons often yield ambiguous conclusions, as alterations could reflect different effects depending on the comparison. Whereas differences found in acutely ill patients could reflect state effects that are due to acute starvation or acute disease-specific factors, they could also reflect underlying traits. Observations in recovered individuals could reflect either an underlying trait or a "scar" due to lasting effects of sustained undernutrition and illness. The co-twin control design (i.e., monozygotic [MZ] twins who are discordant for AN and MZ concordant control twin pairs) affords at least partial disambiguation of these effects.

METHODS

Comprehensive Risk Evaluation for Anorexia nervosa in Twins (CREAT) will be the largest and most comprehensive investigation of twins who are discordant for AN to date. CREAT utilizes a co-twin control design that includes endocrinological, neurocognitive, neuroimaging, genomic, and multi-omic approaches coupled with an experimental component that explores the impact of an overnight fast on most measured parameters.

DISCUSSION

The multimodal longitudinal twin assessment of the CREAT study will help to disambiguate state, trait, and "scar" effects, and thereby enable a deeper understanding of the contribution of genetics, epigenetics, cognitive functions, brain structure and function, metabolism, endocrinology, microbiology, and immunology to the etiology and maintenance of AN.

Coping strategies and stress-induced natural killer cell redistribution in women with eating disorders

BACKGROUND

Patients with eating disorders (ED) are very sensitive and responsive to psychosocial stress. Stress response includes changes in immune cell distribution and may be modulated by the capability to cope with stressors. Thus, the present study sought to analyze the association between coping strategies and immune response (natural killer [NK] cell redistribution following psychosocial stress) in patients with anorexia nervosa (AN) and bulimia nervosa (BN) and healthy controls (HC).

METHOD

Twenty-four AN patients, 29 BN patients, and 58 HC were studied. A multidimensional assessment tool, the COPE Inventory, was used to assess coping strategies. The number of NK cells was quantified in peripheral blood before and after the application of the Trier Social Stress Test (TSST). Potentially mediating variables, such as weight status, severity of eating pathology, depression, anxiety, and impulsivity were controlled.

RESULTS

The three groups differed in intensity and direction of cell redistribution: The TSST was followed in BN patients by a significant decrease in the number of NK cells, whereas HC displayed a moderate decrease and AN a clear increase. Specific correlations between coping strategies and NK cell mobilization were found, especially in BN patients (positive for "planning" and negative for "substance abuse").

CONCLUSION

Recognition and subsequent modification of the dysfunctional coping strategies used by patients with ED could contribute to improving their immune status, strengthening their resilience and increasing their ability to overcome the disease.

Disordered eating behaviors in adolescents with celiac disease

PURPOSE

Celiac disease (CD) is a chronic immune-mediated systemic disease characterized by inflammation and villous atrophy of the small intestine. A strict, lifelong gluten-free diet (GFD) is the only treatment for CD. Disordered eating behaviors (DEBs) prevail in adolescence and young adulthood, and confer a risk of developing into full-blown eating disorders. The aims of the current study were to assess the incidence and risk factors for DEBs among individuals with CD, and to examine an association between adherence to GFD and DEBs.

METHODS

A cohort of 136 individuals with CD responded to a web-mediated survey that assessed DEBs and adherence to a GFD. The survey included demographic data (gender, age, weight, disease duration) and two self-rating questionnaires: the Eating Attitudes Test-26 and the gluten-free diet questionnaire.

RESULTS

DEBs were found in 19% of female and 7% of male responders. These individuals were characterized by being overweight (p = 0.02), of an older age (p = 0.04) and female sex (p = 0.06). Strict adherence to a GFD was reported by 32% of the responders and was not correlated with age, disease duration, age at diagnosis of CD and with being overweight.

CONCLUSIONS

Caregivers should be aware of the increased occurrence of DEBs in adolescents with CD, especially those who are overweight, older and of a female gender.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Anorexia Nervosa and the Immune System-A Narrative Review

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

Eating Disorders: An Evolutionary Psychoneuroimmunological Approach

Eating disorders are evolutionarily novel conditions. They lead to some of the highest mortality rates of all psychiatric disorders. Several evolutionary hypotheses have been proposed for eating disorders, but only the intrasexual competition hypothesis is extensively supported by evidence. We present the mismatch hypothesis as a necessary extension to the current theoretical framework of eating disorders. This hypothesis explains the evolutionarily novel adaptive metaproblem that has arisen when mating motives conflict with the large-scale and easy availability of hyper-rewarding but obesogenic foods. This situation is exacerbated particularly in those contemporary environments that are characterized by sedentary lifestyles, ever-present junk foods, caloric surplus and the ubiquity of social comparisons that take place via social media. Our psychoneuroimmunological model connects ultimate-level causation with proximate mechanisms by showing how the adaptive metaproblem between mating motives and food rewards leads to chronic stress and, further, to disordered eating. Chronic stress causes neuroinflammation, which increases susceptibility to OCD-like behaviors that typically co-occur with eating disorders. Chronic stress upregulates the serotonergic system and causes dysphoric mood in anorexia nervosa patients. Dieting, however, reduces serotonin levels and dysphoric mood, leading to a vicious serotonergic-homeostatic stress/starvation cycle whereby cortisol and neuroinflammation increase through stringent dieting. Our psychoneuroimmunological model indicates that between-individual and within-individual variation in eating disorders partially arises from (co)variation in gut microbiota and stress responsivity, which influence neuroinflammation and the serotonergic system. We review the advances that have been made in recent years in understanding how to best treat eating disorders, outlining directions for future clinical research. Current evidence indicates that eating disorder treatments should aim to reduce the chronic stress, neuroinflammation, stress responsivity and gut dysbiosis that fuel the disorders. Connecting ultimate causes with proximate mechanisms and treating biopsychosocial causes rather than manifest symptoms is expected to bring more effective and sophisticated long-term interventions for the millions of people who suffer from eating disorders.

Association of Childhood-Onset Inflammatory Bowel Disease With Risk of Psychiatric Disorders and Suicide Attempt

IMPORTANCE

Inflammatory bowel disease (IBD) has been associated with psychiatric morbidity in adults, although previous studies have not accounted for familial confounding. In children, IBD has an even more severe course, but the association between childhood-onset IBD and psychiatric morbidity remains unclear.

OBJECTIVE

To examine the risk of psychiatric morbidity in individuals with childhood-onset IBD, controlling for potential confounding shared between siblings.

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study was conducted using data from the Swedish national health care and population registers of all children younger than 18 years born from 1973 to 2013. The study included 6464 individuals with a diagnosis of childhood-onset IBD (3228 with ulcerative colitis, 2536 with Crohn disease, and 700 with IBD unclassified) who were compared with 323 200 matched reference individuals from the general population and 6999 siblings of patients with IBD. Cox proportional hazards regression was used to estimate hazard ratios (HRs) with 95% CIs. Statistical analysis was performed from January 1, 1973, to December 1, 2013.

MAIN OUTCOMES AND MEASURES

The primary outcome was any psychiatric disorder and suicide attempt. Secondary outcomes were the following specific psychiatric disorders: psychotic, mood, anxiety, eating, personality, and behavioral disorders; substance misuse; attention-deficit/hyperactivity disorder; autism spectrum disorders; and intellectual disability.

RESULTS

The study included 6464 individuals with a diagnosis of childhood-onset IBD (2831 girls and 3633 boys; mean [SD] age at diagnosis of IBD, 13 [4] years). During a median follow-up time of 9 years, 1117 individuals with IBD (17.3%) received a diagnosis of any psychiatric disorder (incidence rate, 17.1 per 1000 person-years), compared with 38 044 of 323 200 individuals (11.8%) in the general population (incidence rate, 11.2 per 1000 person-years), corresponding to an HR of 1.6 (95% CI, 1.5-1.7), equaling 1 extra case of any psychiatric disorder per 170 person-years. Inflammatory bowel disease was significantly associated with suicide attempt (HR, 1.4; 95% CI, 1.2-1.7) as well as mood disorders (HR, 1.6; 95% CI, 1.4-1.7), anxiety disorders (HR, 1.9; 95% CI, 1.7-2.0) eating disorders (HR, 1.6; 95% CI, 1.3-2.0), personality disorders (HR, 1.4; 95% CI, 1.1-1.8), attention-deficit/hyperactivity disorder (HR, 1.2; 95% CI, 1.1-1.4), and autism spectrum disorders (HR, 1.4; 95% CI, 1.1-1.7) Results were similar for boys and girls. Hazard ratios for any psychiatric disorder were highest in the first year of follow-up but remained statistically significant after more than 5 years. Psychiatric disorders were particularly common for patients with very early-onset IBD (<6 years) and for patients with a parental psychiatric history. Results were largely confirmed by sibling comparison, with similar estimates noted for any psychiatric disorder (HR, 1.6; 95% CI, 1.5-1.8) and suicide attempt (HR, 1.7; 95% CI, 1.2-2.3).

CONCLUSIONS AND RELEVANCE

Overall, childhood-onset IBD was associated with psychiatric morbidity, confirmed by between-sibling results. Particularly concerning is the increased risk of suicide attempt, suggesting that long-term psychological support be considered for patients with childhood-onset IBD.

Association of chronic and acute inflammation of the mucosa-associated lymphoid tissue with psychiatric disorders and suicidal behavior

Immune dysregulation due to chronic inflammation is a hypothesized risk factor underlying psychiatric disorders and suicidal behavior. Whether tonsillectomy and acute appendicitis used, respectively, as proxies for chronic and acute inflammation within the mucosa-associated lymphoid tissue (MALT) are associated with psychiatric disorders and suicidal behavior is currently unknown. A birth cohort study was conducted including 3,052,875 individuals born in Sweden between 1973 and 2003. We identified 210,686 individuals ever exposed to tonsillectomy and 86,928 individuals ever exposed to acute appendicitis, as well as 317,214 clusters of siblings discordant for tonsillectomy, and 160,079 sibling clusters discordant for acute appendicitis. Outcomes were an aggregate risk of 'any psychiatric disorder', 'any suicidal behavior', 12 individual psychiatric disorders, suicide attempts and deaths by suicide. Tonsillectomy was associated with increased odds of 'any psychiatric disorder' (adjusted odds ratio [aOR] = 1.39; 95% confidence interval (CI) = 1.38-1.41) and 'any suicidal behavior' (aOR = 1.41; 95% CI = 1.37-1.44), and most individual disorders. Acute appendicitis also increased the odds of 'any psychiatric disorder' and 'any suicidal behavior' (aOR = 1.23; 95% CI = 1.20-1.25, and aOR = 1.32; 95% CI = 1.28-1.37, respectively). Exposure to both tonsillectomy and appendicitis was associated with the highest odds of 'any psychiatric disorder' (aOR = 1.70; 95% CI = 1.59-1.82) and 'any suicidal behavior' (aOR = 1.90; 95% CI = 1.70-2.12). In sibling comparisons, the associations were attenuated but remained significant. We conclude that inflammation within the MALT, particularly when chronic, is robustly associated with a broad range of psychiatric disorders and suicidal behavior.

Association of Exposure to Infections in Childhood With Risk of Eating Disorders in Adolescent Girls

IMPORTANCE

Infections are recognized as playing a critical role in the risk of psychiatric disorders and suicidal behavior; however, few studies have evaluated the risk of eating disorders.

OBJECTIVE

To evaluate the association of hospitalization for infections and treatment with anti-infective agents with the risk of an eating disorder diagnosis.

DESIGN, SETTING, AND PARTICIPANTS

A nationwide, population-based, prospective cohort study of 525 643 girls born from January 1, 1989, to December 31, 2006, and followed up until December 31, 2012, was conducted using individual-level data drawn from Danish longitudinal registers. Data were analyzed from January 15 to June 15, 2018, using survival analysis models and adjusted for age, calendar period, parental educational level, and parental history of psychiatric illness.

EXPOSURES

Hospital admission for infections and prescribed anti-infective agents for infections.

MAIN OUTCOMES AND MEASURES

The main outcome of interest was diagnosis of an eating disorder (anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified) in a hospital, outpatient clinic, or emergency department setting. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and accompanying 95% CIs.

RESULTS

The study population consisted of 525 643 adolescent girls: 2131 received a diagnosis of anorexia nervosa (median [range] age, 15.2 [8.6-21.3] years), 711 received a diagnosis of bulimia nervosa (median [range] age, 17.9 [13.4-22.7] years), and 1398 received a diagnosis of an eating disorder not otherwise specified (median [range] age, 15.6 [8.6-21.6] years). A total of 525 643 adolescent girls were followed up for 4 601 720.4 person-years until a mean age of 16.2 years (range, 10.5-22.7 years). Severe infections that required hospitalization were associated with an increased risk of a subsequent diagnosis of anorexia nervosa by 22% (HR, 1.22; 95% CI, 1.10-1.35), bulimia nervosa by 35% (HR, 1.35; 95% CI, 1.13-1.60), and eating disorder not otherwise specified by 39% (HR, 1.39; 95% CI, 1.23-1.57) compared with adolescent girls without hospitalizations for infections. Infections treated with anti-infective agents were associated with an increased risk of a subsequent diagnosis of anorexia nervosa by 23% (HR, 1.23; 95% CI, 1.10-1.37), bulimia nervosa by 63% (HR, 1.63; 95% CI, 1.32-2.02), and eating disorder not otherwise specified by 45% (HR, 1.45; 95% CI, 1.25-1.67) compared with adolescent girls without infections treated with anti-infective agents.

CONCLUSIONS AND RELEVANCE

The findings suggest that hospital-treated infections and less severe infections treated with anti-infective agents are associated with increased risk of subsequent anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified and that future studies should investigate whether these associations are causal and identify the exact mechanisms between infections and subsequent inflammatory processes with eating disorders.

Bidirectional relationship between eating disorders and autoimmune diseases

BACKGROUND

Immune system dysfunction may be associated with eating disorders (ED) and could have implications for detection, risk assessment, and treatment of both autoimmune diseases and EDs. However, questions regarding the nature of the relationship between these two disease entities remain. We evaluated the strength of associations for the bidirectional relationships between EDs and autoimmune diseases.

METHODS

In this nationwide population-based study, Swedish registers were linked to establish a cohort of more than 2.5 million individuals born in Sweden between January 1, 1979 and December 31, 2005 and followed up until December 2013. Cox proportional hazard regression models were used to investigate: (a) subsequent risk of EDs in individuals with autoimmune diseases; and (b) subsequent risk of autoimmune diseases in individuals with EDs.

RESULTS

We observed a strong, bidirectional relationship between the two illness classes indicating that diagnosis in one illness class increased the risk of the other. In women, the diagnoses of autoimmune disease increased subsequent hazards of anorexia nervosa (AN), bulimia nervosa (BN), and other eating disorders (OED). Similarly, AN, BN, and OED increased subsequent hazards of autoimmune diseases.Gastrointestinal-related autoimmune diseases such as, celiac disease and Crohn's disease showed a bidirectional relationship with AN and OED. Psoriasis showed a bidirectional relationship with OED. The previous occurence of type 1 diabetes increased the risk for AN, BN, and OED. In men, we did not observe a bidirectional pattern, but prior autoimmune arthritis increased the risk for OED.

CONCLUSIONS

The interactions between EDs and autoimmune diseases support the previously reported associations. The bidirectional risk pattern observed in women suggests either a shared mechanism or a third mediating variable contributing to the association of these illnesses.

Anorexia nervosa: Gut microbiota-immune-brain interactions

Anorexia nervosa is a psychiatric disorder defined by an extremely low body weight, a devastating fear of weight gain, and body image disturbance, however the etiopathogenesis remains unclear. The objective of the article is to provide a comprehensive review on the potential role of gut microbiota in pathogenesis of anorexia nervosa. Recent advances in sequencing techniques used for microbial detection revealed that this disease is associated with disruption of the composition of normal gut microbiota (dysbiosis), manifested by low microbial diversity and taxonomic differences as compared to healthy individuals. Microorganisms present in the gut represent a part of the so called "microbiota-gut-brain" axis that affect the central nervous system and thus human behavior via the production of various neuroactive compounds. In addition, cells of the immune system are equipped with receptors for these neuroactive substances. Microbiota of the intestinal system also represent a very important antigenic source. These antigens can mimic some host neuropeptides and neurohormones and thus trigger the production of autoantibodies which cross-react with these compounds. The levels and affinities of these antibodies are thought to be associated with neuropsychiatric conditions including anxiety, depression, and eating and sleep disorders. The study of microbiota function in diseases could bring new insights to the pathogenetic mechanisms.

Development and Validation of the Coeliac Disease Food Attitudes and Behaviours Scale

Objectives

Previous studies on coeliac disease suggest that attitudes towards the gluten-free diet may contribute to the development of disordered eating. This study describes the development and validation of the Coeliac Disease Food Attitudes and Behaviours scale (CD-FAB) to measure these behaviours in coeliac disease.

Research Methods and Procedures

Focus groups were used to develop 33 potential questionnaire items. These items were reviewed by service users and then distributed online to 157 adults with coeliac disease. Items were removed based on ceiling/floor effects, high interitem correlations (>0.7) and factor analysis. 11 items were retained. Exploratory factor analysis was then conducted. The psychometric properties of the final version of the CD-FAB were assessed via using an online platform.

Results

The CD-FAB had 11 items distributed across one factor assessing attitudes and behaviours towards food. These factors explained 44.1% of the variance in responding. The CD-FAB and its subscales had high internal consistency (Cronbach's alpha > 0.7) and psychometric validation indicated good convergent and discriminant validity. High scores on the CD-FAB are associated with psychological distress and an impaired quality of life.

Conclusions

The CD-FAB is a reliable and valid measure of food attitudes and behaviours in coeliac disease. As a new disease-specific instrument, it may be a useful tool for evaluating food concerns in individuals with coeliac disease in a clinical setting and for further exploring the development of disordered eating patterns in coeliac disease. Further research is required to assess the full potential of the CD-FAB.

Increased prevalence of disordered eating in the dual diagnosis of type 1 diabetes mellitus and celiac disease

BACKGROUND

Disordered eating behaviors (DEBs) may lead to full blown eating disorders. Both type 1 diabetes mellitus (T1DM) and celiac disease (CD) have been linked to DEBs.

OBJECTIVE

To compare the presence of DEBs between adolescents and young adults with a dual diagnosis of T1DM and CD, and individuals with only one of the diagnoses.

METHODS

Individuals with a dual diagnosis of T1DM and CD ("T1DM + CD group" n = 39), with a diagnosis of T1DM only ("T1DM group" n = 97) and with a diagnosis of CD only ("CD group" n = 267) filled the Eating Attitude Test-26 (EAT-26) questionnaire. Those with T1DM completed in addition to the Diabetes Eating Problem Survey-Revised (DEPS-R).

RESULTS

The study population comprised of 403 individuals, of whom 65% were females. There were no statistically significant differences among the groups in distribution of sex, age, hemoglobin A1c (HbA1c) levels, age of disease diagnosis and duration. The prevalence of DEBs in the T1DM + CD group was 3-fold higher (26.0%) than in the T1DM (8.2%) and CD (8.2%) groups (P = .003). This trend was observed for both females and males. Multivariate analysis demonstrated that the T1DM + CD group had an increased risk for DEBs (odds ratio, OR: 4.7, 95% confidence interval, CI: 1.9-11.2, P = .001) after adjustment for age, sex, and body mass index. Additionally, being female, older and overweight increased the risk for DEBs. HbA1c values were not associated with an increased DEBs rate.

CONCLUSIONS

Individuals with the dual diagnoses of T1DM and CD have an increased likelihood to develop DEBs compared to those with only one of these diagnoses.

Are children with chronic illnesses requiring dietary therapy at risk for disordered eating or eating disorders? A systematic review

OBJECTIVE

Pediatric chronic illnesses (CI) can affect a child's mental health. Chronic illnesses with treatment regimens that specify a therapeutic diet may place the child at increased risk for disordered eating and specific eating disorders (ED). The aim of this review is to examine the relation between diet-treated CI and disordered eating and to determine the order of onset to infer directionality. Diet-treated CI is hypothesized to precede and to be associated with disordered eating.

METHOD

A comprehensive search of empirical articles that examine the relation between diet-treated CI (diabetes, cystic fibrosis, celiac disease, gastrointestinal disorders, and inflammatory bowel diseases) and disordered eating was conducted in Medline and PsycINFO using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A table of the sample's characteristics, ED measures, major pertinent findings, and the onset of CI in relation to ED were provided.

RESULTS

Diet-treated CI was associated with disordered eating and ED. Diet-treated CI had onset prior to disordered eating in most studies, except for inflammatory bowel diseases. Disordered eating and unhealthy weight management practices put children at risk for poor medical outcomes.

DISCUSSION

Interventions for diet-treated CI require a focus on diet and weight, but may increase the risk for disordered eating. Future research is needed to elucidate the mechanisms that transform standard treatment practices into pathological eating, including characteristics and behaviors of the child, parents/care providers, family, and treatment providers.

Eating Disorders, Autoimmune, and Autoinflammatory Disease

OBJECTIVES

Identifying factors associated with risk for eating disorders is important for clarifying etiology and for enhancing early detection of eating disorders in primary care. We hypothesized that autoimmune and autoinflammatory diseases would be associated with eating disorders in children and adolescents and that family history of these illnesses would be associated with eating disorders in probands.

METHODS

In this large, nationwide, population-based cohort study of all children and adolescents born in Denmark between 1989 and 2006 and managed until 2012, Danish medical registers captured all inpatient and outpatient diagnoses of eating disorders and autoimmune and autoinflammatory diseases. The study population included 930 977 individuals (48.7% girls). Cox proportional hazards regression models and logistic regression were applied to evaluate associations.

RESULTS

We found significantly higher hazards of eating disorders for children and adolescents with autoimmune or autoinflammatory diseases: 36% higher hazard for anorexia nervosa, 73% for bulimia nervosa, and 72% for an eating disorder not otherwise specified. The association was particularly strong in boys. Parental autoimmune or autoinflammatory disease history was associated with significantly increased odds for anorexia nervosa (odds ratio [OR] = 1.13, confidence interval [CI] = 1.01-1.25), bulimia nervosa (OR = 1.29; CI = 1.08-1.55) and for an eating disorder not otherwise specified (OR = 1.27; CI = 1.13-1.44).

CONCLUSIONS

Autoimmune and autoinflammatory diseases are associated with increased risk for eating disorders. Ultimately, understanding the role of immune system disturbance for the etiology and pathogenesis of eating disorders could point toward novel treatment targets.

Inflammatory Bowel Disease and Eating Disorders: A systematized review of comorbidity

OBJECTIVE

Research has shown that there is an association between Inflammatory Bowel Disease, anxiety and mood disorders, however little is known about their association with Eating Disorders. In this paper we will present a case of a young female with a comorbid diagnosis of Inflammatory Bowel Disease and Eating Disorder, and then discuss the results from a systematic review of the literature, describing published cases of patients with the same condition.

METHODS

A systematized review of the literature was conducted according to MOOSE guidelines. A computerized literature search of MEDLINE, PsycINFO and EMBASE, and a manual search through reference lists of selected original articles were performed to identify all published case-reports, case series and studies of Inflammatory Bowel Disease and Eating Disorders.

RESULTS

Fourteen articles were included, encompassing 219 cases, including ours. The vast majority were females ranging from 10 to 44years old. Anorexia Nervosa (n=156) and Crohn's Disease (n=129) was the most frequent combination (n=90) reported in the literature. These cases present a poor prognosis because of corticoid refusal, medication abandon and/or deliberate exacerbation of IBD symptoms, in the context of trying to lose weight.

CONCLUSION

Recent evidence suggests there is a possible association between Inflammatory Bowel Disease and Eating Disorders, although the mechanisms involved in its ethiopathogenesis are still unknown. To be aware of this association is important because a delayed diagnosis of this comorbidity may lead to worse prognosis. Further research and a multidisciplinary approach could facilitate earlier diagnosis and provide therapeutic interventions.

Celiac Disease and Anorexia Nervosa: A Nationwide Study

BACKGROUND AND OBJECTIVE

Previous research suggests an association of celiac disease (CD) with anorexia nervosa (AN), but data are mostly limited to case reports. We aimed to determine whether CD is associated with the diagnosis of AN.

METHODS

Register-based cohort and case-control study including women with CD (n = 17 959) and sex- and age-matched population-based controls (n = 89 379). CD (villous atrophy) was identified through the histopathology records of Sweden's 28 pathology departments. Inpatient and hospital-based outpatient records were used to identify AN. Hazard ratios for incident AN diagnosis were estimated by using stratified Cox regression with CD diagnosis as a time-dependent exposure variable. In the secondary analyses, we used conditional logistic regression to estimate odds ratios for being diagnosed with AN before CD.

RESULTS

Median age of CD diagnosis was 28 years. During 1 174 401 person-years of follow-up, 54 patients with CD were diagnosed with AN (27/100 000 person-years) compared with 180 matched controls (18/100 000 person-years). The hazard ratio for later AN was 1.46 (95% confidence interval [CI], 1.08-1.98) and 1.31 beyond the first year after CD diagnosis (95% CI, 0.95-1.81). A previous AN diagnosis was also associated with CD (odds ratio, 2.18; 95% CI, 1.45-3.29). Estimates remained largely unchanged when adjusted for socioeconomic characteristics and type 1 diabetes.

CONCLUSIONS

The bidirectional association between AN diagnosis and CD warrants attention in the initial assessment and follow-up of these conditions because underdiagnosis and misdiagnosis of these disorders likely cause protracted and unnecessary morbidity.