A new study led by researchers at Royal Papworth Hospital NHS Foundation Trust will investigate whether a combined therapy approach for treating obstructive sleep apnoea (OSA) is more effective than current methods.
OSA is a common and serious sleep disorder which affects an estimated 1.5 million adults in the UK .
The usual treatment for OSA is CPAP (continuous positive airway pressure) therapy delivered through a mask, but this can be uncomfortable and intolerable, leading to high drop-out rates.
The study will explore whether combining CPAP with a mandibular advancement device (MAD) is better than using CPAP alone, by improving compliance.
“OSA has a huge impact on people, their health and the economy,” said Dr Tim Quinnell, Consultant Respiratory and Sleep Physician, who is leading the study.
“Poor quality of sleep has a negative impact on daytime functioning and quality of life. This leads to a greater likelihood of excessive daytime sleepiness, poor concentration and memory, irritability, and an increased risk of being involved in road traffic accidents.
“Severe OSA can also contribute to high blood pressure and is associated with a two-and-a-half times higher risk of developing cardiovascular disease, including heart attack and stroke.”
The sleep research team leading the new trial
OSA occurs when the throat muscles relax too much during sleep, causing the upper airway to become excessively floppy and block-off breathing, causing ‘apnoeas’ (breathing pauses).
These apnoeas lead to a drop in blood oxygen level and force the person to briefly wake up so that their airway reopens.
Often people do not know they are waking up, sometimes multiple times a night and for between 10-20 seconds each time.
Symptoms include loud snoring, making gasping or choking noises, and waking up with a headache.
CPAP therapy uses a machine that gently pumps air into a mask worn over the mouth or nose during sleep. For most people this is highly effective at reducing apnoeas, improving symptoms and quality of life.
However, a significant number of patients cannot tolerate CPAP because either the mask or the pressure created can be uncomfortable.
Sometimes the pressure needed to keep the throat open during sleep exceeds what the CPAP machine is able to provide.
“We know that between 20% and 83% of patients cannot tolerate CPAP therapy enough to use it properly,” explained Dr Quinnell, who is the lead researcher for PAPMAT (Positive Airway Pressure Plus Mandibular Advancement Therapy).
“For this significant cohort of patients, their debilitating OSA remains untreated, and that has substantial socioeconomic and healthcare costs in terms of reduced work productivity and close association with other health problems.
“MADs fit around the teeth to hold the lower jaw forward and keep the airway open. On their own they are useful in mild cases of OSA as they are easier to tolerate than CPAP masks.
“This study will investigate whether giving patients a MAD to wear overnight at the same time as CPAP enables a lower pressure to be effective and, if it does, whether this helps more patients to tolerate CPAP better and use it for longer to treat their OSA.”
The study will explore whether combining a CPAP machine with a mandibular advancement device (MAD) will improve patient's sleep apnoea
The study is funded by a £300,000 grant from the ‘Research for Patient Benefit’ arm of the NIHR.
Patients newly started on CPAP who have severe OSA and require a high pressure will be allocated either a CPAP machine alone or a combination of CPAP and MAD for three months.
The effects of the treatment they are on will then be assessed before they are switched to the other treatment method for the same length of time.
The study launched at Royal Papworth Hospital in summer 2022 and recruitment is now open.
“If combined therapy proved useful it would be straightforward to make it widely available because both treatments are already used individually for OSA, potentially benefitting tens of thousands of people in the UK,” added Dr Quinnell.
“It has been estimated that treating all OSA effectively could save the NHS £5 million per year.
“We are very grateful to the NIHR for allocating these funds to Royal Papworth Hospital and we hope that, by working collaboratively with our research partners, the findings from this study will help improve tolerance of treatment for this common and debilitating sleep disorder.”
The study will be led by the Papworth Trials Unit Collaboration, in a partnership between Royal Papworth Hospital’s research and development department, the Medical Research Council Biostatistics Unit, University of Cambridge and King's College London.