Women with bulimia nervosa exhibit attenuated secretion of glucagon-like peptide 1, pancreatic polypeptide, and insulin in response to a meal

Abstract

The eating disorder bulimia nervosa (BN) is characterized by frequent episodes of binge eating, followed regularly by inappropriate compensatory behavior, such as self-induced vomiting. The current investigation was designed to examine possible alterations in the secretion of the gastrointestinal satiety peptides glucagon-like peptide 1 (GLP-1) and pancreatic polypeptide (PP) in women with BN. Twenty-one women with BN and 17 healthy control subjects of comparable age and BMI were recruited. After fasting overnight, the subjects provided blood samples during ingestion of a standardized meal and self-rated their appetite on a visual analog scale. Fasting and meal-related secretion of the incretin GLP-1 and the meal-related feedback signal PP and insulin and glucose as indicators of the metabolic homeostasis were analyzed. Women with BN had significantly lower fasting and postprandial serum concentrations of GLP-1 (P < 0.01) and PP (P < 0.05) than did the control subjects. Furthermore, both the basal (P < 0.001) and peak (P < 0.05) concentrations of insulin were significantly attenuated in the bulimic subjects, whereas glucose concentrations were normal. As a consequence, the bulimic homeostasis model assessment of insulin index values were also lower (P < 0.001). Women with BN secrete abnormally low amounts of GLP-1 and PP, possibly because of the adaption to large meals in the form of enlarged gastric capacity and reduced muscle tone in the gastric wall. Attenuated secretion of these gastrointestinal satiety peptides may play a role in the maintenance of bulimic behavior.