Title: Can Mandibular Advancement Device Treatment For Obstructive Sleep Apnoea Reduce Nocturnal Gastro-Oesophageal Reflux: A Feasibility Study
Funder: Department of Health and Social Care

Abstract: Background: Obstructive Sleep Apnoea (OSA), a condition where airway collapse during sleep results in pauses in breathing, affects 24.5% of the UK population and results in daytime sleepiness, reduced quality of life and increased mortality rates. Over half of these patients will also have gastro-oesophageal reflux disease (GORD) where gastric contents escape back into the oesophagus causing pain, irritation and health complications. These conditions appear to be inter-related and Continual Positive Airway Pressure (CPAP) therapy, the gold standard treatment for OSA to prevent airway collapse, has been shown to reduce GORD. Mandibular Advancement Devices (MADs), a second line but increasingly used therapy for OSA where a gentle jaw thrust is maintained throughout the night, also limit airway collapse. However, whether MADs decrease GORD has not been tested. If they do, this may influence treatment decisions for the 45% of OSA patients who have GORD. Aims and Objectives: The interdisciplinary methodology has not been tested before, therefore the aim of this study is to assess the feasibility of recruitment and the trial protocol. The objectives are to assess patient screening and recruitment rates, willingness to participate, acceptability of the multiple assessments needed to test for improvement in both conditions, and collection of information to inform sample size calculations for a definitive trial. Methods: This will be a single centre, tertiary care based, interdisciplinary, parallel randomised controlled study. Potentially eligible patients referred to the sleep department for investigation for OSA will be contacted by a research dentist/nurse. Interested participants will be pre-screened for GORD using validated questionnaires. Those meeting the screening inclusion criteria will be invited to take part in a simultaneous home sleep study and oesophageal pH monitoring study. Those with confirmed mild/moderate OSA and GORD will be invited to participate in the study. Participants will be randomly allocated to receive either CPAP or MAD therapy. Following successful titration and 3 weeks accustomisation period, participants will receive a follow up simultaneous home sleep study and oesophageal pH monitoring study. The number of patients screened for recruitment, drop-out rates, patient feedback of the study protocol, and information to inform a definitive study design, will be investigated. Timelines for delivery: We anticipate successful screening,recruitment and follow-up to take up to 14 months . This includes 2 months of follow-up after the last recruited patient to complete data collection, which we anticipate will be quicker due to an accelerated treatment pathway. We will need 6 months for data analysis, write up, wider dissemination and feedback, and working with our PPI group and clinical trials unit statistician to develop the definitive trial. Anticipated Impact and Dissemination: Preliminary findings will be disseminated and discussed informally via our PPI co-applicant s charity s social media outlets with the aim to increase awareness and facilitate informal feedback wider than our PPI group. Definitive findings about the feasibility of doing 24 hr pH oesophageal monitoring while doing a home sleep study will be disseminated via clinical and research networks facilitating valuable insights into the simultaneous management of both conditions.

Lay abstract: This project tries to help with two serious problems that patients often suffer from at the same time: Obstructive Sleep Apnoea (OSA) where parts of the airway collapse during sleep, stopping the sufferer from breathing until they wake themselves up, and gastro-oesophageal reflux disease (GORD) where stomach acids backtrack into the mouth causing pain, chronic cough, sore throat and tooth erosion. OSA affects 24.5% of the population and 45% of these suffer from GORD. It is thought that blocking the airway increases pressure in the stomach, forcing acid into the mouth until the patient breathes again. Our PPI group have informed us that if you can manage the sleep apnoea, you can also reduce the stomach acid reflux. The main treatment for OSA is CPAP (Continuous Positive Airway Pressure), a device which blows air down your throat while you sleep keeping the airway open. This is very effective, but patients often struggle to use it, even when they know it is saving their lives. Another treatment is a Mandibular Advancement Device (MAD), where a dental device holds your jaw in a forward position, preventing the airway from collapsing back. Patients prefer the dental device, wearing it for more nights of the week and longer during sleep. CPAP has been shown to reduce night time reflux but this has never been tested for MADs. This information is important for patients to know when deciding which treatment to choose. As nobody has investigated this before, we need to check if the way we recruit participants and test the devices will work. We also need to assess practical things, like if a patient can wear reflux checking devices and sleep devices at the same time. We will see if there will be any problems experienced in the patient journey of the trial and sort through any problems that may come up when multiple teams need to work together. We will recruit 20 patients with both OSA and reflux who will receive CPAP therapy or a MAD. We will check their reflux levels and sleep breathing at night-time while they are wearing ther devices and compare them with their reflux levels at start of the trial. When we are confident that the trial design is good and patients are happy participating in it, we will apply for funding for a bigger trial to check if the MAD can reduce reflux, if they improve patient s quality of life and if this will represent a cost saving to the NHS. We will share our findings to patients, sleep charities, active sleep support communities, clinicians and the academic community with the help of our interdisciplinary team, PPI (public and patient involvement) co-applicant and respective PPI groups.

Research activity codes: 6.3 MEDICAL DEVICES
Health categories: ORAL AND GASTROINTESTINAL;RESPIRATORY