Abstract Introduction Positional obstructive sleep apnea (POSA), a subtype of OSA, is characterized by higher apnea–hypopnea index (AHI) in the supine position. Gastroesophageal reflux disease (GERD) is common among OSA patients and may worsen sleep quality, yet the interaction between POSA and GERD remains unclear. This study aims to investigate the clinical association between POSA and GERD, focusing on GERD severity and its impact on sleep quality and sleep metric differences. Methods Participants undergoing self-paid health evaluations, including an overnight cardiopulmonary coupling (CPC) testing with pulse oximetry, at the National Taiwan University Hospital Health Management Center from 2022 to 2023 were enrolled. GERD severity was assessed using the Los Angeles (LA) classification for erosive esophagitis (EE) and the Reflux Disease Questionnaire (RDQ). Sleep parameters, including AHI, positional differences, and desaturation indices, were obtained from CPC. POSA was defined as AHI-supine/AHI-non-supine ≥ 2 with at least 15 minutes of non-supine sleep. Results A total of 425 participants were analyzed. Among them, 205 (48.2%) had EE (LA Grade A/B/C/D: 183/19/2/1). Additionally, 97 participants (22.8%) had AHI≥15 on CPC testing. After applying the ≥15-minute non-supine time criterion, 76 were classified as POSA and 8 as non-POSA. POSA participants had lower AHI (27.3±8.6 vs. 39.4±16.9, p=0.001), T90% (4.8±6.2 vs. 11.2±13.0, p=0.017), and ESS scores (4.7±3.0 vs. 7.3±3.5, p=0.031). EE prevalence (81.6% vs. 87.5%, p=1.000), EE severity (p=0.607), RDQ scores (3.4±4.8 vs 2±3.4, p=0.417), and PSQI scores (5.1±2.1 vs 5.4±2.9, p=0.771) were similar between POSA and non-POSA groups. Among POSA participants, those with EE were younger (54.8±9.2 vs. 60.8±8.2 years, p=0.027), but no significant differences were observed in BMI, neck circumference, AHI severity, or desaturation. Conclusion In this study, GERD prevalence and severity did not differ between POSA and non-POSA participants. Younger POSA participants were more likely to have EE. Further studies are needed to clarify the complex relationship between GERD and POSA and provide insights of tailored management strategies. Support (if any) Dr. Ping-Huei Tseng reported research grants from the National Taiwan University Hospital (NTUH112-S0320) and the Ministry of Science and Technology (NSTC114-2314-B-002-240-MY3). This study was funded partially by Largan Health AI-Tech (202203075RIPC), which provided home sleep tests and pulse oximetry.
Chen et al. (2026) studied this question.