The influence of serotonin on psychosomatic symptoms in patients with functional dyspepsia

: The pathogenesis of functional dyspepsia is remains unknown. The diagnosis is based on subjective symptoms. However, many effort are being made in searching for the causes and objective indices which could facilitate the diagnosis and the treatment of this disease. AIM: The aim of study was to evaluate the indices of serotonin synthesis and metabolism in patients with functional dyspepsia in relation to psychosomatic symptoms. MATERIALS AND METHODS: The study comprised 30 healthy subjects (group I - control) and 30 patients with functional dyspepsia(group II) as postprandial distress syndrome (PDS), according to Rome Criteria IV. Assessment of the severity of dyspeptic symptoms was performed using a 10-point visual-analogue scale(VAS). All patients completed the Hamilton Depression Scale. Serum serotonin and 5-hydroxyindoleacetic acid (5-HIAA) concentration in urine were measured by ELISA method using IBL antibodies (catalog numbers- RE-59121, RE-59131). RESULTS: Serum serotonin concentration in the control group was 205.1±34.1 ng/ml, and in dyspeptic patients - 154.2±52.9 ng/ml (p<0.001). Significant differences were also found in daily urinary 5-HIAA excretion: 6.88±0.79 mg/24h vs 5.06±1.25 mg/24h, respectively ( p < 0.001). Moreover, a negative correlation was found between serotonin concentration as well as urinary 5-HIAA excretion and severity of depressive symptoms. The correlation between severity of dyspeptic and psychic symptoms was poorly positive. CONCLUSIONS: These results indicate that in patients with functional dyspepsia homeostasis of serotonin is disturbed, and it is in relation to psychosomatic symptoms.