Gastric function in eating disorders

Disorders of the brain-gut interaction and eating disorders

BACKGROUND

Eating disorders (ED) involve both the nervous system and the gastrointestinal tract. A similar double involvement is also found in disorders of the brain-gut interaction (DGBI) and symptoms are sometimes similar.

AIM

To find out where there is an association and a cause-effect relationship, we looked for the comorbidity of DGBI and ED.

METHODS

A systematic review was undertaken. A literature search was performed. Inclusion criteria for the articles retained for analysis were: Observational cohort population-based or hospital-based and case-control studies, examining the relationship between DGBI and ED. Exclusion criteria were: Studies written in other languages than English, abstracts, conference presentations, letters to the Editor and editorials. Selected papers by two independent investigators were critically evaluated and included in this review.

RESULTS

We found 29 articles analyzing the relation between DGBI and ED comprising 13 articles on gastroparesis, 5 articles on functional dyspepsia, 7 articles about functional constipation and 4 articles on irritable bowel syndrome.

CONCLUSION

There is no evidence for a cause-effect relationship between DGBI and ED. Their common symptomatology requires correct identification and a tailored therapy of each disorder.

Which Symptoms, Complaints and Complications of the Gastrointestinal Tract Occur in Patients With Eating Disorders? A Systematic Review and Quantitative Analysis

BACKGROUND

Eating disorders (ED) such as anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED) are often accompanied by a variety of psychological and physical comorbidities. Gastrointestinal (GI) symptoms are a classical feature in most patients with ED. The heterogeneity of studies on this topic is high, making it difficult to have a clear overview. The aim of this systematic review is therefore to provide an overview of subjectively and objectively measured differences and changes in the GI tract in patients with EDs, along with the occurrence of GI complications.

METHODS

A systematic literature search was conducted in PubMed, Web of Science, and Google Scholar to find all relevant studies examining GI problems in AN, BN, and BED. Quantitative analyses were performed for objective GI physiology measures where applicable.

RESULTS

The review differentiated between ED types and also between studies that report GI outcomes of ED in (i) human studies with an ED diagnosis excluding case reports that provide an overview of GI problems in ED and (ii) case reports with an ED diagnosis describing rare GI complications in ED. GI symptoms and impaired gastric transit times were frequent features of EDs with specific differences found for the ED types. During the time course of treatment, GI symptoms changed and/or improved but not completely. GI complications extended the range of GI problems observed, including a variety of serious complications such as gastric dilatation.

CONCLUSIONS

Problems of the GI tract are frequent in patients with ED and it is likely that they complicate therapy, especially in patients with AN.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42019100585.

Relationship of body weight with gastrointestinal motor and sensory function: studies in anorexia nervosa and obesity

Background

Whether gastrointestinal motor and sensory function is primary cause or secondary effect of abnormal body weight is uncertain. Moreover, studies relating continuous postprandial sensations of satiation to measurable pathology are scarce. This work assessed postprandial gastrointestinal function and concurrent sensations of satiation across a wide range of body weight and after weight change.

Methods

Patients with anorexia nervosa (AN) and obesity (OB) were investigated in reference to normal weight controls (HC). AN were additionally investigated longitudinally. Gastric emptying, antral contractions and oro-cecal transit after ingestion of a solid meal were investigated by MRI and ¹³C-lactose-ureide breath test. The dependency of self-reported sensations of satiation on the varying degree of stomach filling during gastric emptying was compared between groups.

Results

24 AN (BMI 14.4 (11.9–16.0) kg/m²), 16 OB (34.9 (29.6–41.5) kg/m²) and 20 HC (21.9 (18.9–24.9) kg/m²) were studied. Gastric half-emptying time (t₅₀) was slower in AN than HC (p = 0.016) and OB (p = 0.007), and a negative association between t₅₀ and BMI was observed between BMI 12 and 25 kg/m² (p = 0.007). Antral contractions and oro-cecal transit were not different. For any given gastric content volume, self-reported postprandial fullness was greater in AN than in HC or OB (p < 0.001). After weight rehabilitation, t₅₀ in AN tended to become shorter (p = 0.09) and postprandial fullness was less marked (p < 0.01).

Conclusions

A relationship between body weight and gastric emptying as well as self-reported feelings of satiation is present. AN have slower gastric emptying and heightened visceral perception compared to HC and OB. Longitudinal follow-up after weight rehabilitation in AN suggests these abnormalities are not a primary feature, but secondary to other factors that determine abnormal body weight.

Trial registration

Registered July 20, 2009 at ClinicalTrials.gov (NCT00946816).

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0560-y) contains supplementary material, which is available to authorized users.

Can eating disorders cause functional gastrointestinal disorders?

Functional gastrointestinal disorders (FGIDs) are very common (up to 98%) in patients with an eating disorder (ED). Boyd et al. discuss in this issue of Neurogastroenterology & Motility that FGIDs can persist independently on the outcome of the ED. Their findings leave room for speculation on the mechanisms underlying FGIDs in patients with an ED. FGIDs result from a complex interaction of biological, psychosocial and social factors. The altered eating behavior seen in EDs is strongly associated with disturbed gastrointestinal sensitivity and motor physiology. Moreover, psychiatric co-morbidities in ED patients are also frequently found in FGIDs. The motor and sensitivity disturbances together with psychiatric co-morbidities can lay the foundation of a FGID. Once established the psychological and physiological disturbances can perpetuate and strengthen each other resulting in a FGID that can persist independently of the ED that originally caused the motor and sensitivity disturbances.

Dysfunctional eating in the eating disorders

Aberrant eating patterns in the eating disorders have been observed across various laboratory-based and clinical studies. It is now clear that problems in experiencing and expressing hunger, appetite, and satiety in anorexia and bulimia nervosa are likely to perpetuate the disorders once established. Whether problems in appetite regulation are primary or secondary to the development of the disorders is unknown. In studies examining indices of appetite regulation after treatment, there still remain significant levels of eating abnormality. This suggests that the main goals of treatment, including restoration of body weight in anorexia nervosa, abstaining from dieting in anorexia or bulimia nervosa, and reducing or abstaining from binge eating, do not correct some features of abnormal eating. The efficacy of nutritional counseling and specific nutritional management programs have been tested, and these seem to produce positive outcomes in improving eating behavior. Direct behavioral interventions to change eating patterns also have been examined, and these too seem to produce benefits that may be incorporated into CBT. Greater collaboration and cooperation between researchers and clinicians in addressing dysfunctional eating in the eating disorders will highlight improvements in treatment for identifiable eating abnormalities and will further the understanding of the human appetite system.

Effects of preloads of differing energy and macronutrient content on eating behavior in bulimia nervosa

Evidence suggests that bulimics demonstrate blunted satiety possibly due to repeated episodes of overeating. This suggestion was tested further by comparing responses to yogurt preloads differing in carbohydrate and fat relative to a lower energy control yogurt in 12 bulimics and 12 age- and weight-matched controls. Participants were tested on three occasions at lunchtime. On each occasion, appetite and mood were rated before and after receiving a lunch of raspberry yogurt (350 g). Covert manipulation of energy and nutrient content was achieved by matching the yogurts on sensory properties and formulating a control yogurt (161 kcal), a high-fat version (357 kcal: 65% calories from fat), and a high-carbohydrate version (357 kcal: 81% calories from carbohydrate). Although there were no differential effects of the preloads on intake of an ad libitum test meal given 5 hr later in either the control or bulimic groups, there were significant differences in test meal energy intake between groups. On average and with all conditions combined, bulimics ate significantly fewer calories (775 +/- 167 kcal) than controls (1182 +/- 94 kcal) and consumed a greater percentage of calories from carbohydrate than controls. Bulimics restricted their intake relative to controls, and chose foods low in fat. This study provides further evidence of restricted eating in bulimia nervosa when the opportunity to purge is not available. Furthermore, the present study suggests that intake by bulimics is not influenced by nutrient content per se but by consideration of the caloric value of foods and the consequences of eating certain foods for weight control.