BACKGROUND: Diaphragmatic breathing training (DBT) improves symptoms in patients with gastroesophageal reflux disease (GERD), but the pathophysiological mechanism is unclear. The aim of this retrospective study was to assess the impact of DBT on individual components of antireflux barrier using high resolution esophageal manometry (HRM) in patients with GERD symptoms.
METHODS: We analyzed our prospectively collected data of adult patients with persistent typical or atypical reflux symptoms receiving DBT between June 2019 and October 2023. Patients who underwent an initial HRM and completed the follow-up examination after at least three months of DBT were included. Dynamic neuromuscular stabilization techniques were applied to all patients during the training. Esophagogastric junction (EGJ) function was assessed using basal lower esophageal sphincter (LES) pressure and EGJ contractile integral (EGJ-CI). As the diaphragm activity contributes not only to EGJ contractility but also to EGJ compliance, we defined a composite parameter “EGJ function optimization“, which was achieved in patients who either increased EGJ-CI or simultaneously increased both basal LES and integrated relaxation pressure (IRP) after DBT. Esophageal clearance was evaluated using distal contractile integral (DCI) and percentage of ineffective motility (IEM). Change in reflux symptoms after DBT was also assessed.
RESULTS: 51 patients were enrolled, 37 were male, median age was 45 years (range 25-77), median BMI was 24 kg/m2 (range 19-32). Median duration of DBT was 10 months (range 3-24). Basal LES pressure increased after DBT (mean basal LES before DBT 25.95 ± 9.21 vs. 29.11 ± 10.28 mmHg after DBT; p=0.02). There was a trend to increase EGJ-CI after DBT (mean EGJ-CI before 53.89 ± 27.04 vs. 60.01 ± 31.04 mmHg*cm after DBT; p=0.11). EGJ function optimization was achieved in 33 of 51 patients, resulting in a success rate of 64.7% (95% CI:51.0% to 76.4%). Patients significantly improved esophageal contractility and decreased percentage of IEM (mean DCI before DBT 1074.22 ± 820.47 vs. 1294.12 ± 1002.42 mmHg*cm*s after DBT; p=0.01, mean IEM was 36.35 ± 37.66 vs. 27.92 ± 31.02% after DBT; p=0.03). Symptom improvement of at least 50% was reported by 44 of 51 patients (86.3%) after DBT.
CONCLUSION: In patients with reflux symptoms, DBT improves both EGJ function and esophageal clearance. The role of DBT in the complex management of gastroesophageal reflux disease represents a topic for further research.

Figure 1 shows changes in individual parameters evaluating the esophagogastric junction (EGJ) function and esophageal contractility on HRM before and after diaphragmatic breathing training (DBT); basal lower esophageal sphincter (LES) pressure, EGJ contractile integral (EGJ-CI), distal contractile integral (DCI), percentage of ineffective motility (IEM)

Figure 2 displays esophagogastric junction (EGJ) function and esophageal contractility using HRM before and after diaphragmatic breathing training (DBT) in a patient with hypotensive lower esophageal sphincter (LES) (left a, b) and a patient with ineffective esophageal motility (right c, d), Chicago classification v4.0 was used in evaluation of HRM. Left: a; before DBT: hypotensive EGJ with basal LES pressure 9.1 mmHg, EGJ-CI 5.85 mmHg*cm, IRP 6.3 mmHg, b; after DBT: basal LES pressure 28.4 mmHg, EGJ-CI 36.59 mmHg*cm, IRP 14.2 mmHg. Right: c; before DBT: 100% ineffective esophageal motility, DCI 197.5 mmHg*cm*s, d; after DBT: 54% weak peristalsis, DCI 523.7 mmHg*cm*s