Olanzapine-induced weight gain in anorexia nervosa: Involvement of leptin and ghrelin secretion?

SummaryBackgroundOlanzapine (OLA) administration has been reported to induce weight gain in experimental animals and humans, through not yet fully defined mechanisms of action. Aim of this study was to determine whether in patients with Anorexia Nervosa (AN) OLA induces weight gain through the modulation of the hunger-satiety regulatory peptides leptin and ghrelin.MethodsTwenty anorexic probands received a 3 months course of cognitive-behavioral psychotherapy and programmed nutritional rehabilitation, combined with OLA PO (2.5 mg for 1 month and 5 mg for 2 months) in ten patients and with placebo PO (PL) in the other 10. Weight, measured as body mass index (BMI), leptin and ghrelin plasma values were monitored before starting the therapy and then monthly for 3 months. Plasma leptin was measured by ELISA, and plasma ghrelin by radioimmunoassay.ResultsBMI increased significantly but not differently in both treatment groups. Leptin and ghrelin secretion did not change during the course of the treatments. No correlations were observed between BMI values and leptin and ghrelin levels.ConclusionsOur data suggest that the weight gain observed in our OLA-treated patients was not linked to drug administration. Moreover, leptin and ghrelin secretions were not responsible for BMI changes.