Randomised controlled trial of the effect of mandibular advancement splint (MAS) versus positive airway pressure (PAP) therapy on blood pressure in obstructive sleep apnoea

INTERVENTION: The study will compare the gold standard treatment for Obstructive Sleep Apnoea, namely Continuous Positive Airway Pressure (CPAP), to oral appliance therapy. CPAP treatment involves the delivery of pressurised air from a pump to the nose via tubing and a nose mask. The pressurised air acts to prevent the airway from collapsing during sleep. Oral appliance therapy involves a titratable intra‐oral device worn during sleep, that advances the mandible to improve upper airway calibre and function. The oral appliance being used is a Mandibular Advancement Splint (MAS). Following appropriate acclimatisation to both treatment modalities, patients will undergo 1 month intervention with each treatment (cross‐over design) in order to compare the health effects of the treatments. Subjects will be encouraged to use each device every night during sleep. Following treatment on the first device, there will be a 2 week washout period before subjects are crossed over to the second device. CONDITION: obstructive sleep apnoea PRIMARY OUTCOME: 24 hour mean arterial blood pressure (MAP) SECONDARY OUTCOME: 24 hr Systolic (SBP) and Diastolic (DBP) blood pressures Central blood pressure (Central SBP and Augmentation Index) Compliance Driving simulator performance (AusEd) Mean Waking and Sleeping blood pressures ‐ Mean Arterial Pressure (MAP), SBP and DBP Polysomnographic measures of treatment efficacy at the end of each 1 month treatment period (Apnoea Hypopnoea Index (AHI), Minimum Oxygen Saturation, Arousal Index) Quality of life (SF‐36, Functional Outcomes of Sleep Questionnaire (FOSQ)) Side‐effects (nature and frequency) Subjective Daytime Sleepiness (Epworth Sleepiness Scale) INCLUSION CRITERIA: Presence of at least 2 symptoms of obstructive sleep apnoea (snoring, fragmented sleep, witnessed apneas, daytime sleepiness); proven obstructive sleep apnoea on polysomnography (AHI>10)