Ghrelin and leptin responses to food ingestion in bulimia nervosa: implications for binge-eating and compensatory behaviours.

Abstract

Ghrelin and leptin are endogenous peripheral proteins involved in the regulation of eating behaviour. In particular, ghrelin stimulates hunger and promotes food ingestion, whereas leptin increases satiety and reduces food consumption. Therefore, alterations in the physiology of these peptides may play a role in the pathogenesis of eating disorders such as bulimia nervosa. In the present study, we investigated ghrelin and leptin responses to food ingestion in patients with bulimia nervosa. Nine symptomatic drug-free bulimic women and 12 age-matched healthy women ingested a meal of 1207 kcal (60% carbohydrates, 23% fat and 17% proteins) at 12.00 a.m. and underwent blood sample collection before and 45, 60, 90, 120 and 180 min after the meal. Plasma levels of ghrelin, leptin, insulin and glucose were measured. In healthy women, circulating ghrelin exhibited a drastic decrease after the food intake whereas, in bulimic patients, this response was significantly blunted. No difference between the two subjects groups was observed in post-prandial profiles of plasma leptin, insulin and glucose. The lack of a leptin response to food ingestion, in both bulimic and healthy women, is compatible with the role of this peptide as long-term rather than short-term modulator of eating behaviour. The blunted ghrelin response to food ingestion may support the occurrence in bulimic subjects of an impaired suppression of the drive to eat following a meal. This may have implications for binge-eating.