In humans, the cephalic phase response to food ingestion consists mostly of vagal efferent activation, which promotes the secretion of entero-pancreatic hormones, including ghrelin. Since symptomatic patients with bulimia nervosa (BN) are characterized by increased vagal tone, we hypothesized an enhanced ghrelin secretion in the cephalic phase of vagal stimulation. Therefore, we investigated ghrelin response to modified sham feeding (MSF) in both BN and healthy women. Six drug-free BN women and 7 age-matched healthy females underwent MSF with initially seeing and smelling a meal, and then chewing the food without swallowing it. Blood samples were drawn immediately before and after MSF for hormone assay. Circulating ghrelin increased after MSF in both groups with BN individuals exhibiting a greater ghrelin increase, which positively correlated with the patients' weekly frequency of binge-purging. These results show for the first time an increased ghrelin secretion in the cephalic phase of vagal stimulation in symptomatic BN patients, likely resulting in a potentiation of the peripheral hunger signal, which might contribute to their aberrant binge-purging behavior.
2009 Elsevier Ltd. All rights reserved.