Effect of Continuous Positive Airway Pressure on Chronic Cough in Patients with Obstructive Sleep Apnea and Concomitant Gastroesophageal Reflux

Background: Obstructive sleep apnea (OSA) and/or gastroesophageal reflux (GER) may be the contributors to chronic cough in patients with OSA and concomitant GER. This study aimed to explore whether continuous positive airway pressure (CPAP), antireflux treatment and lifestyle modifications improve chronic cough in patients with OSA and concomitant GER. Methods: Patients with OSA and concomitant GER who also experienced chronic cough were enrolled, and were divided into two groups. Patients who were treated with general treatment (antireflux treatment and lifestyle modifications) as the control group, and patients who were treated with CPAP and general treatment as the treatment group. Effects of different treatments on chronic cough were assessed, and the association among chronic cough, GER and OSA was evaluated by Pearson's correlation analysis. Results: The Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale were better in the treatment group after 1 week of treatment; further, the improvement became stronger with the duration of therapy. The gastroesophageal reflux disease questionnaire, visual analog scale (VAS) for cough, and daytime and nighttime cough symptom scores significantly improved in both groups after treatment, whereas this improvement was more significant in the treatment group. Significant associations between the apnea-hypopnea index (AHI) and VAS, weak acid reflux and VAS, and weak acid reflux and AHI were observed. Conclusion: CPAP improved the symptoms of chronic cough and GER in patients with OSA and concomitant GER. AHI and weak acid reflux may be important factors affecting the therapeutic effect of chronic cough in patients with OSA and concomitant GER.