Effect of Inspiratory Muscle Training on Symptom Severity and Quality of Life in Non-Erosive Reflux Disease

The IMT protocol consisted of home-based high-intensity daily training - two cycles of 30 breaths with a 1-minute rest between sets, twice a day for 4 weeks using an IMT Threshold device (Threshold IMT Philips® Respironics, Inc). The IMT was performed twice a day, 7 days/week, for 4 weeks. The study group performed IMT at 60% of their baseline MIP and was adjusted weekly based on the modified Borg scale from 4 to 6 regarding respiratory effort performed during the session, while the control group performed a sham-IMT without applied resistance. Patients are evaluated before the inspiratory muscle training and after 4 weeks of training.

Inclusion criteria

• A clinical diagnosis of NERD,
• No erosive lesions on endoscopy,
• Presence of reflux symptoms for at least 3 months.

Exclusion criteria

• Current use of proton pump inhibitors (PPIs) or failure to complete a minimum 2-week washout period before enrollment.
• With known gastroduodenal ulcers
• Diagnosed with erosive esophagitis
• With hiatal hernia
• With a history of gastrointestinal malignancy
• With infectious or inflammatory gastrointestinal diseases
• With malabsorption syndrome or gastrointestinal obstruction
• With a history of major gastrointestinal surgery (including anti-reflux, gastric, or duodenal surgery)
• With systemic sclerosis or other systemic connective tissue diseases
• With severe cardiovascular, pulmonary, renal, or hepatic disease
• With chronic respiratory diseases such as asthma or COPD
• Having had an acute respiratory tract infection within the past 4 weeks
• With neuromuscular diseases
• With active tuberculosis
• Pregnancy