Investigation of peptide YY and ghrelin responses to a test meal in bulimia nervosa

Background Gut-derived peptides, such as peptide YY (PYY) and ghrelin that regulate the initiation and termination of meals, could play a role in the altered eating behavior of patients with bulimia nervosa (BN). Therefore, we aimed to assess plasma PYY and ghrelin responses to a test meal in symptomatic bulimics. Methods Ten healthy women and nine women with BN underwent blood sample collections before and after the ingestion of a test meal of 1300 Kcal (with 15% carbohydrates, 10% proteins, and 75% fat) at 12:00 noon. Plasma total PYY, ghrelin, insulin, and glucose were assayed. Results As compared with healthy women, bulimics exhibited a significantly blunted increase of circulating PYY (p< .007) and a significantly reduced suppression of plasma ghrelin (p< .0004) after the test meal. No significant differences emerged in food-induced plasma insulin and glucose changes between the two groups. Plasma ghrelin suppression after the meal was significantly correlated with plasma PYY increase. Conclusions We replicated our previous findings of an altered ghrelin response to food ingestion in people with BN and showed for the first time a blunted PYY increase after food consumption in these patients. These findings support the occurrence in BN of a profound dysregulation of some peripheral regulatory mechanisms involved in the short-term regulation of feeding behavior that might be involved in the pathophysiology of their binge eating behavior.