Health Outcomes of Continuous Positive Airway Pressure versus Oral Appliance Treatment for Obstructive Sleep Apnea

TLDR

Continuous positive airway pressure (CPAP) and mandibular advancement device (MAD) therapy are commonly used to treat obstructive sleep apnea (OSA). The study compared health effects after one month of optimal CPAP versus MAD therapy in patients with moderate‑to‑severe OSA. In a randomized crossover trial of 108 participants, each received one month of CPAP and one month of MAD, with 24‑hour mean arterial pressure as the primary outcome and cardiovascular, neurobehavioral, and quality‑of‑life measures assessed. CPAP reduced apnea‑hypopnea index more than MAD, but MAD had higher compliance; 24‑hour mean arterial pressure was similar between treatments, and both improved sleepiness, driving performance, and disease‑specific quality of life, with MAD slightly better on four general quality‑of‑life domains, leading to overall comparable health outcomes after one month. The trial (ACTRN 12607000289415) was registered at https://www.anzctr.org.au, and the similar effectiveness of CPAP and MAD is attributed to CPAP’s greater efficacy offset by lower compliance.

Abstract

Rationale: Continuous positive airway pressure (CPAP) and mandibular advancement device (MAD) therapy are commonly used to treat obstructive sleep apnea (OSA). Differences in efficacy and compliance of these treatments are likely to influence improvements in health outcomes.Objectives: To compare health effects after 1 month of optimal CPAP and MAD therapy in OSA.Methods: In this randomized crossover trial, we compared the effects of 1 month each of CPAP and MAD treatment on cardiovascular and neurobehavioral outcomes.Measurements and Main Results: Cardiovascular (24-h blood pressure, arterial stiffness), neurobehavioral (subjective sleepiness, driving simulator performance), and quality of life (Functional Outcomes of Sleep Questionnaire, Short Form-36) were compared between treatments. Our primary outcome was 24-hour mean arterial pressure. A total of 126 patients with moderate-severe OSA (apnea hypopnea index [AHI], 25.6 [SD 12.3]) were randomly assigned to a treatment order and 108 completed the trial with both devices. CPAP was more efficacious than MAD in reducing AHI (CPAP AHI, 4.5 ± 6.6/h; MAD AHI, 11.1 ± 12.1/h; P < 0.01) but reported compliance was higher on MAD (MAD, 6.50 ± 1.3 h per night vs. CPAP, 5.20 ± 2 h per night; P < 0.00001). The 24-hour mean arterial pressure was not inferior on treatment with MAD compared with CPAP (CPAP-MAD difference, 0.2 mm Hg [95% confidence interval, −0.7 to 1.1]); however, overall, neither treatment improved blood pressure. In contrast, sleepiness, driving simulator performance, and disease-specific quality of life improved on both treatments by similar amounts, although MAD was superior to CPAP for improving four general quality-of-life domains.Conclusions: Important health outcomes were similar after 1 month of optimal MAD and CPAP treatment in patients with moderate-severe OSA. The results may be explained by greater efficacy of CPAP being offset by inferior compliance relative to MAD, resulting in similar effectiveness.Clinical trial registered with https://www.anzctr.org.au (ACTRN 12607000289415).