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.