Patterns of esophageal acidification and impairment of esophageal motility in gastroesophageal reflux disease and Barrett's esophagus

Background. Gastroesophageal reflux disease (GERD) has a high prevalence worldwide and plays a major role in the development of Barrett’s esophagus (BЕ) and, as a consequence, esophageal adenocarcinoma. Aims: to evaluate the patterns of esophageal acidification and esophageal motility in patients with BЕ in comparison with various GERD phenotypes and control subjects. Methods. 100 patients were examined: 31 patients with nonerosive reflux disease (NERD), 20 patients with erosive reflux disease (ERD), 17 patients with BE, 32 healthy individuals who made up the control group. All patients underwent 24-hours pH-impedance and high-resolution esophageal manometry. Results. According to the 24-hour pH-impedanсe, the total time with pH < 4 in the esophagus was 1.9% (95% CI: 1.1−2.7) in control patients, 11.6% (95% CI: 8.76–13.4) in the NERD group, 19.35 (95% CI: 12.70−26.05) in the ERD group and 28% (95% CI: 10.04–40.96) in patients with BE (p < 0.05). The average number of acid refluxes was 18.0 (95% CI: 10.99−23.0) in the control group, 58.0 (95% CI: 42.34−71.0) in the group with NERD, 78.5 (95% CI: 65.34−103.93) in the group with ERD and 89.0 in patients with BE (95% CI: 67.03−118.72). Significant differences in the listed indicators were noted when comparing patients with BE and control individuals, as well as the NERD group (p < 0.05). The number of acidic refluxes was significantly correlated with the time on the acidification of the esophagus (r = 0.5439; p < 0.05). The median time of chemical clearance was 1.55 min (95% CI: 1.19−2.0) in control subjects, 2.4 min (95% CI: 1.65−2.94), in the NERD group, 2.85 min (95% CI: 1.80−3.84) in the ERD group, and 3 min (95% CI: 2.1−4.68) in the BE group. The analysis of the mean nocturnal baseline impedance (MNBI) revealed a tendency to decrease the values in patients with GERD relative to the control subjects, and there was a decrease in the values of MNBI as the severity of GERD ― from NERD to ERD and BE (p < 0.05). Manometric signs of hiatal hernia and/or hypotension of the lower esophageal sphincter were more often registered in the groups of patients with ERD (70%) and BE (65%) than in patients with NERD (32%) and in control group (12%). In addition, the frequency of such esophageal motor disorders as ineffective motility and absent contractility were significantly more often observed in patients with ERD and BE (75% and 77%, respectively) compared with patients with NERD (22.5%) and control subjects (12,5%). Conclusions. Increase in level of total time with pH < 4, number of acid refluxes, slowing chemical clearance, reduced values of MNBI, as well as disorders of the structure and function of the esophagogastric junction and motility of the esophagus are associated with the severity of аcid pathology of the esophagus.