TOPLINE:

Combining supplemental oxygen with mandibular advancement device (MAD) therapy significantly reduced obstructive sleep apnea (OSA) severity compared with sham treatment and offered a 14% greater improvement than MAD alone in patients with moderate-to-severe OSA.

METHODOLOGY:

• Researchers conducted a multicenter randomized crossover trial with 41 participants with moderate-to-severe OSA (median age, 54 years; women-to-men ratio, 14:27; 80% treatment-naive) to evaluate whether supplemental oxygen combined with MAD reduces OSA severity compared with MAD alone.
• Patients received four interventions in random order — supplemental oxygen (4 L/min via nasal cannula), MAD, combination therapy (MAD plus oxygen), and sham (room air at 4 L/min) — with each treatment scheduled 1 week apart and separated by a 6-night washout period.
• The primary outcome was the apnea-hypopnea index (AHI), including hypopneas without desaturation or arousals, and secondary outcomes were the arousal index, patient-reported sleep quality (assessed via the visual analog scale), and changes in blood pressure.

TAKEAWAY:

• The combination of MAD and supplemental oxygen provided a greater reduction in AHI than MAD alone (difference in change from baseline, -14%; P = .009).
• Compared with sham, the combination decreased arousal index scores and increased visual analog scale scores for sleep quality; however, compared with MAD alone, the combination did not offer a significant improvement.
• All interventions reduced physiologic burdens compared with sham; however, only hypoxic and heart rate burdens showed greater reductions with combination therapy than with MAD alone.

IN PRACTICE:

“Combined upper airway and ventilatory control therapies could also provide an alternative treatment approach beyond the combined upper airway plus upper airway modalities currently being explored with considerable early success,” the authors wrote.

SOURCE:

This study was led by Bradley A. Edwards, PhD, Department of Physiology, Biomedical Discovery Institute, Monash University in Melbourne, Australia. It was published online on October 2, 2025, in the European Respiratory Journal.

LIMITATIONS:

The study was limited by its acute, single-night intervention design with multiple treatments closely spaced, leaving uncertainty about long-term efficacy. Additionally, physiologic measurements were conducted using gold-standard signals at baseline, which may not directly reflect clinical estimates that could be more susceptible to measurement noise.

DISCLOSURES:

This study was supported by the National Heart Foundation of Australia, the American Heart Association, and the National Institutes of Health. BlueSom donated devices for the study. Several authors reported having relationships — including grants, consultancies, and co-inventorship of intellectual property — with device or pharmaceutical companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.