Effect of CPAP Therapy on Symptoms of Nocturnal Gastroesophageal Reflux among Patients with Obstructive Sleep Apnea

Study Objectives: Nocturnal gastroesophageal reflux (nGER) is common among patients with obstructive sleep apnea (OSA). Previous studies demonstrated that continuous positive airway pressure (CPAP) reduces symptoms of nGER. However, improvement in nGER symptoms based on objective CPAP compliance has not been documented. We have examined the polysomnographic characteristics of patients with nGER and OSA and looked for association of OSA severity and CPAP compliance with improvement in nGER symptoms. Methods: We interviewed 85 veterans with OSA to assess their daytime sleepiness (Epworth Sleepiness scale [ESS]) and nGER symptom frequency after their polysomnography and polysomnographic data were reviewed. At 6 months' follow-up, ESS score, nGER score, and CPAP machine compliance data were reassessed. Data from 6 subjects were dropped from final analysis due to their initiation of new medication for nGER symptom since the initial evaluation. Results: Sixty-two of 79 (78%) patients complained of nGER symptoms during initial visit. At baseline, nGER score was correlated with sleep efficiency (r = 0.43), and BMI correlated with the severity of OSA (r = 0.41). ESS and nGER improved (p < 0.0001) in all patients after 6 months, but more significantly in CPAP compliant patients. A minimum CPAP compliance of 25% was needed to achieve any benefit in nGER improvement. Conclusions: Nocturnal gastroesophageal reflux is common among patients with OSA which increases sleep disruption and worsens the symptoms of daytime sleepiness. CPAP therapy may help improve the symptoms of both nocturnal acid reflux and daytime sleepiness, but adherence to CPAP is crucial to achieve this benefit.