Is it an eating disorder, gastrointestinal disorder, or both?

Shared genetic influences between eating disorders and gastrointestinal disease in a large, population-based sample of adult women and men

BACKGROUND

Some preliminary research suggests higher rates of gastrointestinal disease in individuals with eating disorders (EDs). However, research is limited, and it remains unknown what etiologic factors account for observed associations. This was the first study to examine how EDs and dimensional ED symptoms (e.g. body dissatisfaction, binge eating) are phenotypically and etiologically associated with gastrointestinal disease in a large, population-based twin sample.

METHODS

Adult female (N = 2980) and male (N = 2903) twins from the Michigan State University Twin Registry reported whether they had a lifetime ED (anorexia nervosa, bulimia nervosa, or binge-eating disorder) and completed a measure of dimensional ED symptoms. We coded the presence/absence of lifetime gastrointestinal disease (e.g. inflammatory bowel disease) based on responses to questions regarding chronic illnesses and medications. We first examined whether twins with gastrointestinal disease had higher rates of EDs and ED symptoms, then used correlated factors twin models to investigate genetic and environmental contributions to the overlap between disorders.

RESULTS

Twins with gastrointestinal disease had significantly greater dimensional ED symptoms (β = 0.21, p < 0.001) and odds of a lifetime ED (OR 2.90, p = 0.001), regardless of sex. Shared genetic factors fully accounted for the overlap between disorders, with no significant sex differences in etiologic associations.

CONCLUSIONS

Comorbidity between EDs and gastrointestinal disease may be explained by overlap in genetic influences, potentially including inflammatory genes implicated in both types of disorders. Screening for gastrointestinal disease in people with EDs, and EDs in those with gastrointestinal disease, is warranted.

Circulating anti-hypothalamus antibodies in celiac patients: tissue transglutaminase friend or foe?

Celiac disease (CD) is an autoimmune disease with inflammatory characteristics, having a condition of chronic malabsorption, affecting approximately 1% of the population at any age. In recent years, a concrete correlation between eating disorders and CD has emerged. Hypothalamus plays a central role in determining eating behaviour, regulating appetite and, consequently, food intake. One hundred and ten sera from celiac patients (40 active and 70 following a gluten-free diet) were tested for the presence of autoantibodies against primate hypothalamic periventricular neurons by immunofluorescence and by a home-made ELISA assay. In addition, ghrelin was measured by ELISA. As control, 45 blood serums from healthy age matched were analysed. Among active CD, all patients resulted positive for anti-hypothalamus autoantibodies and sera showed significantly higher levels of ghrelin. All of the free-gluten CD were negative for anti-hypothalamus autoantibodies and had low levels of ghrelin, as well as healthy controls. Of interest, anti-hypothalamic autoantibodies directly correlate with anti-tTG amounts and with mucosal damage. In addition, competition assays with recombinant tTG showed a drastically reduction of anti-hypothalamic serum reactivity. Finally, ghrelin levels are increased in CD patients and correlated with anti-tTG autoantibodies and anti-hypothalamus autoantibodies. This study demonstrates for the first time the presence of anti-hypothalamus antibodies and their correlation with the severity of the CD. It also allows us to hypothesize the role of tTG as a putative autoantigen expressed by hypothalamic neurons.

Gastrointestinal complaints in patients with anorexia nervosa in the timecourse of inpatient treatment

BACKGROUND

In patients with anorexia nervosa (AN), gastrointestinal (GI) symptoms are common and usually improve during or after nutritional rehabilitation. It is unclear when exactly GI symptoms change in the timecourse of treatment and to which extent. In this study, we analyzed the timecourse of GI symptoms and their relation to disease-specific, demographic, anthropometric, and psychological factors in inpatients with AN.

METHODS

In weekly intervals, the Gastrointestinal Symptom Rating Scale (GSRS) was completed, and body weight was measured over a mean of 9.5 weeks in inpatients with AN. A total of four self-report questionnaires assessing psychological factors were completed before and after inpatient treatment. Data from 38 inpatients with AN were analyzed using mixed linear models.

RESULTS

Abdominal pain and constipation improved significantly in the timecourse with 0.085 (p = 0.002) and 0.101 (p = 0.004) points per week on the GSRS and were predicted to normalize after 13 (p = 0.002) and 17 (p = 0.004) weeks, respectively. Total GI symptoms tended to normalize after 25 weeks (p = 0.079). Indigestion (borborygmus, abdominal distension, eructation, flatulence) was the most severely pathological symptom at admission and did not improve significantly (p = 0.197). Diarrhea and reflux were, on average, not pathological at admission and remained stable during treatment. In addition to treatment time, the strongest predictors were ED pathology at admission for the development of abdominal pain, constipation, reflux, and total GI symptoms; stress for the development of constipation and total GI symptoms; and depression for constipation.

CONCLUSIONS

Informing patients with AN about the course of GI symptoms and their improvement during weight rehabilitation may help support compliance during treatment.

Evaluating disorders of gut-brain interaction in eating disorders

OBJECTIVE

Eating disorders commonly co-occur with gastrointestinal problems. This case-control study aimed to (a) document the prevalence of disorders of gut-brain interaction (DGBI) in eating disorders, (b) examine the specific impact of disordered eating behaviors on the risk of DGBI, and (c) explore the impact of current eating disorder psychopathology on DGBI.

METHOD

We included 765 cases with eating disorders and 1,240 controls. DGBI were assessed via the ROME III questionnaire. Prevalences of DGBI were calculated across eating disorder diagnoses (anorexia nervosa, bulimia nervosa, and multiple eating disorders) and in controls. The association between disordered eating behaviors and DGBI was examined using logistic regression models. Lastly, we compared the total number of DGBI in individuals with high versus low current eating disorder symptoms.

RESULTS

A large majority (88.2-95.5%) of individuals with eating disorders reported at least one DGBI and 34.8-48.7% reported three or more DGBI. Of the DGBI categories, functional bowel disorders were the most commonly endorsed category, and of the individual DGBI, irritable bowel syndrome was the most frequently reported (43.9-58.8%). All investigated disordered eating behaviors showed a positive association with most DGBI categories. Finally, individuals reporting high current eating disorder symptoms reported higher mean number of DGBI (3.03-3.34) than those with low current symptoms (1.60-1.84).

DISCUSSION

The directionality and mechanisms underlying the nature of the relationship between gastrointestinal and eating disorder symptoms is worthy of further study and clinicians should adopt an integrated approach by attending to both gastrointestinal and eating disorder symptoms in their patients.

Characteristics of avoidant/restrictive food intake disorder in a general paediatric inpatient sample

OBJECTIVE

Although patients with avoidant/restrictive food intake disorder (ARFID) often consult general paediatric services initially, existing literature mostly concentrated on intensive eating disorder treatment settings. This cross-sectional study sought to describe symptoms of ARFID and their associations with eating disorder psychopathology, quality of life, anthropometry, and physical comorbidities in a general paediatric sample.

METHODS

In N = 111 patients (8-18 years) seeking treatment for physical diseases, prevalence of ARFID-related restrictive eating behaviours was estimated by self-report and compared to population-based data (N = 799). Using self-report and medical record data, further ARFID diagnostic criteria were evaluated. Patients with versus without symptoms of ARFID based on self-report and medical records were compared in diverse clinical variables.

RESULTS

The prevalence of self-reported symptoms of ARFID was not higher in the inpatient than population-based sample. Only picky eating and shape concern were more common in the inpatient than population-based sample. Although 68% of the inpatient sample reported any restrictive eating behaviours, only 7% of patients showed symptoms of ARFID based on medical records in addition to self-report, particularly those with underweight, without significant effects for age, sex, and medical diagnoses.

DISCUSSION

The study revealed the importance of considering ARFID within the treatment of children and adolescents with physical diseases, especially for those with underweight. Further research is needed to replicate the findings with interview-based measures and to investigate the direction of effects in ARFID and its physical correlates.

Prolonged constipation and diarrhea in childhood and disordered eating in adolescence

OBJECTIVES

Gastrointestinal problems are common in all eating disorders; however, the extent to which these problems predate the onset of eating disorders is not clear. We explored longitudinal associations between childhood gastrointestinal problems and adolescent disordered eating, and assessed whether observed associations are potentially causal or due to familial confounding factors.

METHODS

Data from a population-based Swedish twin sample were used to investigate associations between parent- and self-reported protracted constipation and diarrhea in childhood and adolescence, and later disordered eating, measured by the Eating Disorders Inventory-2 (EDI). Linear regression models were used to investigate the associations. Possible familial confounding was explored by using a within-twin pair analysis.

RESULTS

We found that those who reported a history of constipation at age 15 scored 5.55 and 5.04 points higher, respectively, on the EDI total score at age 15 and 18, compared with those without constipation. Those reporting a history of diarrhea at age 15 scored 5.15 points higher, and the group reporting both problems scored 9.52 points higher on the EDI total score at age 15 than those reporting no problems. We observed that the association between constipation and disordered eating was attenuated in the within-twin pair analysis, but remained positive.

CONCLUSIONS

Gastrointestinal problems in childhood and adolescence are significantly associated with disordered eating. Associations were partly due to familial confounding, but might also be consistent with a causal interpretation. Clinicians should be aware of the increased risk of disordered eating when following children and adolescents who present with gastrointestinal problems.

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.

Anorexia nervosa of the restrictive type and celiac disease in adolescence

BACKGROUND

Anorexia nervosa (AN) is usually present in adolescence with symptoms partially overlapping celiac disease (CD), but the relationship between these two conditions has received little attention in the literature. The aim of this work was to explore this relationship, considering if CD could be associated with specific baseline AN-related clinical features.

METHODS

In this retrospective study, 82 adolescent female out- and inpatients with AN of the restrictive type (ANr), according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria, were recruited. CD diagnosis and related serology were recorded, including tissue transglutaminase type-2 antibodies, endomysial antibodies, and antibodies against deamidated forms of gliadin peptides. Eating disorder inventory-3, Children's Depression Inventory, body mass index, age, and disease duration data recorded at the time of blood withdrawal were also obtained from each patient.

RESULTS

Five (6.1%) subjects presented a CD disorder associated with AN: none of the collected psychometric measures was significantly correlated with any CD-related parameter or characterized as a specific subgroup.

CONCLUSION

CD diagnosis or serology does not relate to ANr clinical or demographic characteristics. However, a slight increase in prevalence with respect to the general population might be hypothesized and possibly elucidated by further studies with an appropriate design.

Gastrointestinal Manifestations of Eating Disorders

Individuals with eating disorders, including anorexia nervosa and bulimia nervosa, may present with a range of gastrointestinal (GI) manifestations. The oral cavity, salivary glands, GI tract, pancreas, and liver can be impacted by nutritional restrictive and binge/purging behaviors. Complications are often reversible with appropriate nutritional therapy. At times, however, the complications in these disorders may be severe, irreversible and even life threatening. Given the often covert nature of eating disorders, the practitioner must be attentive to subtle clues that may indicate their presence. Extensive diagnostic evaluations of the GI manifestations of eating disorders should be used only when nutritional rehabilitation does not remedy the problems.

Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity

Functional, molecular and genetic neuroimaging has highlighted the existence of brain anomalies and neural vulnerability factors related to obesity and eating disorders such as binge eating or anorexia nervosa. In particular, decreased basal metabolism in the prefrontal cortex and striatum as well as dopaminergic alterations have been described in obese subjects, in parallel with increased activation of reward brain areas in response to palatable food cues. Elevated reward region responsivity may trigger food craving and predict future weight gain. This opens the way to prevention studies using functional and molecular neuroimaging to perform early diagnostics and to phenotype subjects at risk by exploring different neurobehavioral dimensions of the food choices and motivation processes. In the first part of this review, advantages and limitations of neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), pharmacogenetic fMRI and functional near-infrared spectroscopy (fNIRS) will be discussed in the context of recent work dealing with eating behavior, with a particular focus on obesity. In the second part of the review, non-invasive strategies to modulate food-related brain processes and functions will be presented. At the leading edge of non-invasive brain-based technologies is real-time fMRI (rtfMRI) neurofeedback, which is a powerful tool to better understand the complexity of human brain-behavior relationships. rtfMRI, alone or when combined with other techniques and tools such as EEG and cognitive therapy, could be used to alter neural plasticity and learned behavior to optimize and/or restore healthy cognition and eating behavior. Other promising non-invasive neuromodulation approaches being explored are repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS). Converging evidence points at the value of these non-invasive neuromodulation strategies to study basic mechanisms underlying eating behavior and to treat its disorders. Both of these approaches will be compared in light of recent work in this field, while addressing technical and practical questions. The third part of this review will be dedicated to invasive neuromodulation strategies, such as vagus nerve stimulation (VNS) and deep brain stimulation (DBS). In combination with neuroimaging approaches, these techniques are promising experimental tools to unravel the intricate relationships between homeostatic and hedonic brain circuits. Their potential as additional therapeutic tools to combat pharmacorefractory morbid obesity or acute eating disorders will be discussed, in terms of technical challenges, applicability and ethics. In a general discussion, we will put the brain at the core of fundamental research, prevention and therapy in the context of obesity and eating disorders. First, we will discuss the possibility to identify new biological markers of brain functions. Second, we will highlight the potential of neuroimaging and neuromodulation in individualized medicine. Third, we will introduce the ethical questions that are concomitant to the emergence of new neuromodulation therapies.

Is it an eating disorder or achalasia or both? A literature review and diagnostic challenges

INTRODUCTION

Achalasia is a rare oesophageal motility disorder characterized by physical, behavioural and psychosocial features that are strikingly similar to eating disorders (ED).

METHOD

A literature search of PubMed and Google Scholar identified 36 cases of achalasia from 11 countries misdiagnosed as ED between 1980 and 2013.

RESULTS

On average, the typical misdiagnosed case was an 18-year-old female with an average weight loss of 16.2 kg. Vomiting behaviour in achalasia was distinguished by occurring after both solids and liquids, occurring in public, and worsening at night or while lying down, and was associated with pain relief. Manometric investigations of oesophageal functioning in clinical ED samples are few and have shown little evidence of dysmotility.

DISCUSSION

Achalasia and ED share numerous clinical features including weight loss and vomiting. Pain associated with swallowing difficulties may lead to an increasingly restricted pattern of eating and food avoidance. Increased awareness of achalasia in ED treatment settings can help facilitate detection of achalasia, thereby reducing treatment delay.