Effects of Upper Airway Muscle Training on OSA
Condition: Obstructive Sleep Apnea
MeSH terms: Apnea; Sleep Apnea Syndromes; Sleep Apnea, Obstructive
Study type: Interventional

Summary: 
      Obstructive sleep apnea (OSA) is a common disorder characterized by recurrent collapse of the
      upper airway during sleep. OSA patients have a small upper airway that is kept patent during
      wakefulness by a compensatory increase in upper airway (UA) dilator muscle (e.g.
      genioglossus) activity. At sleep onset this compensation is reduced or lost, resulting in
      upper airway narrowing or collapse. Previous studies of upper airway muscle training showed
      variable results on OSA, but so far there has not been any practical, long-term, systematic
      upper airway muscle training developed or studied as the treatment of OSA. In theory,
      strengthening the upper airway muscle with exercise training in theory helps maintain a
      patent airway during sleep. Therefore, investigators aim to test the hypothesis: 1) UA muscle
      training can improve sleep apnea in some patients with OSA, including those already receiving
      treatment with PAP or oral appliance therapy. 2) Muscle training is a viable therapy for a
      definable subset of OSA patients. Investigators hypothesize that patients with OSA who have
      mild or moderately compromised upper airway anatomy will benefit the most. 3)There will be a
      positive association between the changes in muscle function and improvement in OSA severity.
    

Detailed description: 
      Obstructive sleep apnea (OSA) is a common disorder characterized by recurrent collapse of the
      upper airway during sleep, which leads to recurrent arousal and subsequent daytime
      sleepiness. The most commonly accepted reason for the initiation of obstructive respiratory
      events in OSA is that patients have a small upper airway that is kept patent during
      wakefulness by a compensatory increase in upper airway dilator muscle (e.g. genioglossus)
      activity. At sleep onset this compensation is reduced or lost, resulting in upper airway
      narrowing or collapse.

      Upper airway (UA) muscle training appears to have some benefit in OSA with improvement in the
      AHI, although the current data shows variable results, particularly when publication bias is
      taken into account. Many remain skeptical about these data based on clinical experience and
      prior negative studies (which remain largely unpublished). Moreover, previous positive
      studies involved exercises that are usually impractical to be continued in the long-term.

      Therefore, investigators will undertake a rigorous assessment of a practical UA muscle
      training on OSA. Investigators will recruit patients with OSA that are wither
      unable/unwilling to use CPAP, as well as those who are already on treatment with PAP or oral
      appliances. The exercises include 4 steps: step 1 is to put on an individualized fitted oral
      retainer device to guide the exercise; step 2 is to push the tongue towards the hard palate
      to press the movable part of the oral retainer device for 4 minutes; step 3 is to touch the
      hard palate using the middle part of the tongue, hold for 10 seconds and repeat it for 4
      minutes; step 4 is to remove the retainer device and brush the tongue gently on both sides
      for 2 minute. The exercise will take 20 minutes a day (10 minutes in the morning and 10
      minutes in the afternoon/evening).

      Investigators will study the effect of upper airway (UA) muscle training on OSA severity,
      muscle strengh and endurance. Investigators aim to determine the characteristics of OSA
      patients most likely to benefit from UA muscle training and the association between changes
      in muscle function and OSA severity.
    

Intervention name(s): Upper Airway Muscle Exercise; Sham Exercise
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Patients will use an individualized oral retainer device for upper airway muscle training exercises daily for 20 minutes each day (10 minutes in the morning and 10 minutes in the afternoon/evening) for 6 weeks.; Patients will be given an individualized oral retainer device and instructed to do deep breathing exercise twice daily for 6 weeks.
Allocation: Randomized
Intervention model: Factorial Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Obstructive Sleep Apnea; Exercise; Upper airway muscle