Serotonin Blood Level in Children with Overlapping of Irritable Bowel Syndrom and Functional Dyspesia

Background: The epidemiological studies of the prevalence of functional dyspepsia (FD) and irritable bowel syndrome (IBS) showed a wide range (13–87%) of the overlap between them (Fujiwara, 2014). The main clinical symptom in children with FD as well as IBS is abdominal pain, which has different characteristics, but similar origins. Both of these functional gastrointestinal disorders are largely dependent on the condition of the gut motility and visceral hypersensitivity on a background of neurohormonal dysregulation. Serotonin plays an important role in these processes taking part in nociceptive transmission and regulation of a pain impulse (J Talley Nicholas, 2013).

Objective: Evaluation of serotonin blood level in children with overlapping of IBS and FD.

Methods: The blood concentration of serotonin was measured by the fluorometric assay in 43 children, aged from 10 to 15 years old with IBS (the main group) and 10 healthy individuals of the same age (the control group). The main group was divided into two subgroups: 23 children with overlapping IBS and FD and 20 children with IBS only. The diagnosis was established clinically according to the Rome IV Diagnostic Criteria (2016). The accuracy of the diagnosis was confirmed by the laboratory tests and low and upper endoscopies.

Results: The mean value of the serotonin blood level in children with overlapping IBS and FD was 3,56 ± 0,02 mkmol/L and it markedly exceeds (р<0,01) this parameter in the control group (1,45±0,15 mkmol/L). It was also higher (р<0,05) than the same one in the patients with IBS only (2,62 ± 0,26 mkmol/L).

Conclusions: We have found the higher blood level of serotonin in children with overlapping of IBS and FD compared with the ones with IBS only. It should be taken into account for management of such patients.