Aim of the study. To study the effect of connective tissue dysplasia (CTD) symptoms’ influence at gastric acidity disorder in patients with acid-dependent diseases. Material and methods. 151 patients were included in the randomized controlled comparative one-stage study. All participants had general clinical examination, determination of CTD features, esophagogastroduodenoscopy, abdominal organs ultrasound, 24-hour pH-metry. Statistical processing of obtained data was carried out using the methods of parametric and nonparametric analysis. Classification of objects based on the results of 24-hour pH-metry was carried out using the program Deductor Studio Academic 5.3 using neural network algorithms by constructing Kohonen maps. Analysis of the effect of CTD signs at the formation of gastric acidity varieties was carried out using the technology of data mining - the construction of decision trees. Results. A unique set of signs of CTD influencing the development of gastric acidity variants is revealed, the strength and direction of this influence are determined. Hypoacid variant with high probability develops with gastroptosis, with the probability of medium strength (23%) – with deformation of the chest. The biliary variant develops with the probability of medium strength (27%) with duodenal-gastric reflux and gall-bladder deformity (30%). Reflux variant develops with a probability of medium strength (18%) with a decrease in body weight below 66.5 kg. The hyperacid variant develops with a probability of moderate strength with a decrease in body weight below 66.5 kg (15%) and without deformation of the chest (12%). The normoacid variant of gastric acidity develops with the probability of medium strength (21%) in the absence of dolichostenomelia. Conclusion. The obtained data on the diagnosis of gastric acidity variants can be used in the treatment of patients with acid-dependent diseases and signs of CTD.

Keywords: connective tissue dysplasia, 24-hour pH-metry, varieties of gastric acidity