Risk factors for various clinical variants of irritable bowel syndrome

Abstract

Introduction . Irritable bowel syndrome (IBS) affects a significant portion of the population worldwide. The disease is characterized by a multifactorial pathogenesis and a variable clinical picture, in the center of which is abdominal pain and violations of the act of defecation. Our work shows the relationship between the functional polymorphism of the serotonin reuptake transporter (5-HTTLPR of the SLC6A4 gene) and the features of myoelectric activity (MEA) of the small intestine in various clinical variants of IBS. Purpose — to study clinical, functional and genetic features in patients with IBS and on their basis to determine significant risk factors for the formation of various IBS variants. Materials and methods . 148 patients were examined: 79 patients with IBS (group 1), including 45 patients with IBS with a predominance of diarrhea (group 1a) and 34 patients with IBS with a predominance of diseases (group 1b), 10 healthy volunteers (group 2), 59 patients of therapeutic profile without IBS (group 3). The diagnosis of “IBS” was established according to the Rome criteria III revision. All of them thoroughly studied peripheral electrogastroenterography (PEGEG) and groups of patients 1 and 3 — genetic analysis of the 5-HTTLPR polymorphism of the SLC6A4 gene. Results . In the diarrheal variant of IBS, the 5-HTTLPR promoter more often contains the S allele associated with a decrease in the function of the serotonin reuptake transporter. The risk factors for the formation of clinical variants of IBS include: gender, polymorphic variants of the 5-HTTLPR gene SLC6A4 and the values of the postprandial coefficient of myoelectric activity (MEA) at the frequencies of “ileum” and “jejunum”. Conclusions . The revealed relationships between the motor-evacuation function (MEF) of the gastrointestinal tract and polymorphism of the serotonin transporter gene demonstrate the pathophysiological significance of these associations in the development of IBS and its clinical variability. Features of the functioning and genetic features of the serotonergic system deserve further study, which is promising for improving the diagnostic and therapeutic approach to patients with IBS.