Volume-Oriented Incentive Spirometry-Assisted Diaphragmatic Breathing Exercise for Functional Heartburn or Reflux Hypersensitivity

Overview

The goal of this pilot randomized controlled trial is to determine whether volume-oriented incentive spirometry-assisted diaphragmatic breathing exercise (VIS-assisted DBE) can improve reflux-related symptoms and health-related quality of life in adults with functional heartburn (FH) or reflux hypersensitivity (RH). The main questions it aims to answer are: Does VIS-assisted DBE reduce reflux-related symptoms compared with usual care? Does VIS-assisted DBE improve health-related quality of life compared with usual care? Researchers will compare VIS-assisted DBE plus usual care with usual care alone to determine whether the intervention provides additional benefits in symptom relief and quality of life. Participants will: Complete baseline clinical evaluations and symptom questionnaires. Be randomly assigned to either the VIS-assisted DBE group or the usual care group. Receive either VIS-assisted diaphragmatic breathing exercises twice daily for 20 minutes over a 4-week period in addition to usual care, or usual care alone. Complete follow-up assessments after the 4-week intervention, including symptom and quality-of-life questionnaires

Functional heartburn (FH) and reflux hypersensitivity (RH) are disorders of gut-brain interaction characterized by persistent reflux-related symptoms despite the absence of significant esophageal acid exposure or structural abnormalities. Although proton pump inhibitors are widely used for reflux-related disorders, many patients with FH and RH continue to experience persistent symptoms, resulting in reduced health-related quality of life. Current evidence suggests that altered esophageal sensory processing, autonomic nervous system dysfunction, and impaired gut-brain axis regulation contribute to symptom generation in these disorders. Diaphragmatic breathing exercise has emerged as a promising non-pharmacological intervention that may improve diaphragmatic function, enhance vagal activity, and reduce reflux-related symptoms. Volume-oriented incentive spirometry (VIS) provides visual feedback during breathing training and may improve the consistency and effectiveness of diaphragmatic breathing. However, evidence regarding the therapeutic effects of VIS-assisted diaphragmatic breathing exercise in patients with FH or RH remains limited. This prospective, parallel-group, pilot randomized controlled trial is designed to evaluate the clinical effectiveness of VIS-assisted diaphragmatic breathing exercise in adults with FH or RH. Participants will be randomly assigned to receive either VIS-assisted diaphragmatic breathing exercise in addition to usual care or usual care alone. The study will assess whether the intervention improves reflux-related symptoms and health-related quality of life compared with usual care. The findings of this study are expected to provide preliminary evidence regarding the feasibility and potential clinical benefits of VIS-assisted diaphragmatic breathing exercise as an adjunctive non-pharmacological treatment for functional heartburn and reflux hypersensitivity, and to support the design of future larger randomized controlled trials.