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Key points
- Obstructive sleep apnoea can be caused by narrowed airways and unstable breathing
- Until now, randomised trials targeting both causes have been lacking
- A Monash-led trial has found benefits in combining treatments for both
Combined treatments for both aspects of obstructive sleep apnoea (OSA) – a compromised airway anatomy and unstable breathing – have shown promise in a Monash and Harvard-led trial.
Published in the European Respiratory Journal, the study found that treating both aspects with multiple treatments markedly reduced severity compared with either treatment alone.
An estimated five per cent of Australians have sleep apnoea, including about 1 in 4 men aged over 30. In the over-30s, it's about twice as common in men than women.
Associate Professor Brad Edwards, from the Monash University School of Psychological Sciences, said OSA was attributed not only to the anatomical tendency of the upper airway – particularly the pharynx – to narrow or collapse during sleep, but also an instability in the regulation of breathing.
Associate Professor Edwards said the study tested whether combining a ventilatory control intervention (supplemental oxygen) with an upper airway mechanical intervention mandibular advancement device, known as MAD, improved treatment efficacy.
"We did this because we know that OSA is due to a combination of anatomical and non-anatomical causes," he said. "The MAD targets the anatomical cause while oxygen helps target a leading but underappreciated non-anatomical cause.
"Mandibular advancement devices are commonly used to treat OSA, while supplemental oxygen is not commonly used; it is often used for other respiratory disorders such as COPD and emphysema. This is the first time this combination has been tried in patients with OSA."
The multicentre randomised crossover trial saw 41 patients with moderate-to-severe OSA undergo a comprehensive overnight sleep study with four interventions involving oxygen, MAD, combination therapy, and a sham (i.e. room air).
"Combining a ventilatory control intervention (supplemental oxygen) with an upper airway intervention (MAD) is a promising approach to markedly attenuate OSA severity beyond that offered by each intervention alone," the researchers found.
Senior author Scott Sands, an Associate Professor of Medicine from Brigham and Women's Hospital in Boston, said targeting multiple causes of OSA significantly decreased severity, measured using a number of different metrics, compared to each therapy alone.
"Now we need larger trials targeted to selected patients, but this is the first convincing evidence that going after multiple causes of OSA at the same time could have real benefits for patients," Assistant Professor Sands said.
"If widely adopted, it could be a bit like people with high blood pressure taking 2-3 medications to control it, with each targeting different biological pathways."
Read the research paper: https://doi.org/10.1183/13993003.01320-2025
