Depressed concentrations of oxytocin and cortisol in children with recurrent abdominal pain of non-organic origin.

The purpose of the present study was to measure plasma concentrations of oxytocin, cortisol and prolactin in children with recurrent abdominal pain of non-organic origin (RAP). Forty children with RAP and 34 controls, matched for age and sex, participated in the study. A blood sample was collected after an overnight fast in association with clinical examinations. Oxytocin, cortisol and prolactin levels were determined by radioimmunoassay (RIA). Oxytocin and cortisol concentrations in the children with RAP were found to be significantly reduced compared with those of the controls (approximately 24 versus 63 pmol/l for oxytocin and 160 versus 300 nmol/l for cortisol, respectively). The low oxytocin and cortisol levels persisted at a second examination 3 months later. No significant differences in the prolactin levels were observed between RAP and controls.