This study will evaluate the impact on blood glucose of the use of an oral appliance to treat obstructive sleep apnea (OSA) in individuals with Type 2 diabetes. An oral appliance is similar to a sports mouth guard or an orthodontic retainer and is an alternative treatment to continuous positive airway pressure (CPAP) for OSA. Oral appliance therapy has not been evaluated in patients with Type 2 diabetes with respect to glycemic outcomes. This will be a 1:1 randomized controlled trial: The experimental group will receive the oral appliance and the control group will receive a sham device over the course of approximately 5 months.

OSA is quite common in individuals with T2DM, occurring in as many as 60-80% of patients. The standard treatment for OSA is with the use of a CPAP machine. The CPAP provides an air pressure to keep the airways opened during sleep so that a person with OSA can breathe normally. When used appropriately, the CPAP improves sleepiness and quality of life. However, about half of the patients who receive a CPAP prescription cannot tolerate it and thus remain untreated and are potentially at increased cardiovascular and diabetes risk. In light of this, this study aims to see if the use of an alternative treatment for OSA, oral appliance therapy, where adherence is generally superior to CPAP, will improve cardiometabolic outcomes in individuals with Type 2 diabetes. This pilot trial will primarily examine feasibility and assess recruitment rates.

Inclusion Criteria:

• Diagnosis of T2DM using current Canadian guidelines
• OSA with AHI > 10 events/hour using current American Academy of Sleep Medicine (AASM) criteria for scoring respiratory events

Exclusion Criteria:

• On treatment for OSA within the past 3 months
• Professional drivers or patients with an increased risk of driving-related accidents from clinical interview or severe subjective sleepiness (Epworth sleepiness scale greater than 15)
• Sleep apnea with any of the following features: highly severe OSA (AHI>50 and oxygen desaturation index > 50), severe hypoxemia (SpO2<80% for >10% of recording time), central sleep apnea or Cheyne-Stokes respirations with a central apnea index >10 events/hour
• Coexisting sleep disorder other than OSA
• Active cardiovascular disease, including angina, arrhythmia or congestive heart failure
• Insufficient dentition or significant periodontal disease or other contraindication for OAT as determined by dentist qualified in OSA treatment
• Active and significant psychiatric disease
• BMI>35
• Regular use of sedatives or narcotics

Towards meta-analysis data