CCK, ghrelin, and PYY responses in individuals with binge eating disorder before and after a cognitive behavioral treatment (CBT)

BACKGROUND: Several abnormalities of peripheral neuropeptide release in obese and obese patients with binge eating disorder (BED) compared to controls have been reported: lower baseline, meal-induced, and post-meal ghrelin concentrations, decreased baseline PYY, and a blunted PYY response to meals. In contrast, obese BED individuals show comparable CCK releases. We aimed at clarifying the role of peripheral hormones in BED, to assess the impact of a cognitive behavioral treatment (CBT) for BED on neuropeptides and to investigate the predictive value of neuropeptide concentrations on binge eating status after treatment. METHODS: Blood samples of 14 female and 4 male overweight to obese participants with BED were collected repeatedly for CCK, PYY, and ghrelin analysis in the morning after an 8-h fasting period. BED participants and 19 controls matched for age and body mass index (BMI) were served a standardized breakfast. The release of neuropeptides was compared to corresponding measures of controls. RESULTS: Fasting baseline values of all three peptides were comparable between BED participants and controls. BED participants revealed a higher meal-induced increase in CCK and PYY compared to controls, whereas ghrelin was not affected. Following a short-term CBT the neuropeptide concentration of the BED participants was comparable to before CBT. The hormone release prior to treatment had no predictive value on binge eating status after the treatment. CONCLUSIONS: With respect to CCK and PYY our results point to a combined conditioned response from the central nervous system and the gut to initiate the release of satiety hormones in order to prevent further bingeing after initial food intake. The release of neuropeptides does not predict short-term treatment outcome. Future prospective studies should investigate whether neuropeptide secretion influences the course of BED in the long term.