Abstract
INTRODUCTION: This study aimed to evaluate the effects of continuous positive airway pressure (CPAP) therapy on gastroesophageal reflux disease (GERD) symptom severity and obstructive sleep apnea (OSA) severity in patients diagnosed with both conditions over a one-month period, using validated tools to examine CPAP adherence and adverse events. MATERIALS AND METHODS: This prospective, single-center cohort study was conducted at the Department of Respiratory Medicine between May 2024 and March 2025. Eighty-nine adults aged 18-75 years with moderate-to-severe OSA (apnea-hypopnea index as AHI ≥ 15 events/h) confirmed by polysomnography and GERD diagnosed via clinical symptoms or endoscopic evidence were enrolled. The exclusion criteria included prior CPAP use, severe comorbidities, and inability to tolerate CPAP use. Baseline assessments included the Gastroesophageal Reflux Disease Questionnaire (GERD-Q) for GERD symptoms, Epworth Sleepiness Scale (ESS) for daytime sleepiness, and polysomnography for AHI, peripheral oxygen saturation (SpO(2)), and oxygen desaturation index (ODI). The patients received auto-titrating CPAP therapy with telemedicine support. Follow-up at one month included repeat GERD-Q, ESS, polysomnography, and CPAP adherence data (defined as >4 h/night on ≥70% of nights). Statistical analyses were performed using the Mann-Whitney U test, mediation analysis, and multivariable linear regression analysis, with significance set at p < 0.05. RESULTS: The study included 89 patients, with 55 male patients (61.8%) and 34 (38.2%) female patients. Of the 89 patients (mean age 55.04 ± 6.48 years, mean body mass index 31.84 ± 2.5 kg/m²), 72 (80.9%) achieved adequate CPAP adherence. Adequate adherence significantly reduced the GERD-Q scores (p < 0.05), AHI (p < 0.05), ODI (p < 0.05), and ESS scores (p < 0.05), with no significant change in SpO(2) (p = 0.393). No adverse events were noted. Smoking and right-side/supine sleep positions negatively predicted GERD improvement, whereas the ESS reduction was a positive predictor. Mediation analysis showed that CPAP's effect on GERD was independent of changes in AHI, ODI, or ESS. CONCLUSION: Adequate CPAP adherence significantly improved GERD and OSA severity without adverse effects, supporting its use as the primary therapy for patients with both conditions. Targeted interventions addressing smoking and sleep positions may further enhance these outcomes.