Airway Muscle Training for Obstructive Sleep Apnea
Condition: Obstructive Sleep Apnea
MeSH terms: Apnea; Sleep Apnea Syndromes; Sleep Apnea, Obstructive
Study type: Interventional

Summary: 
      The purpose of this research study is to determine if muscle training will improve snoring
      and obstructive sleep apnea. Subjects will receive a sleep study to determine the severity of
      their apnea. After this study, subjects will be randomly assigned to one of two groups. The
      first group will receiving a breathing trainer that may strengthen the muscles used to breath
      in and out. The second group will be receive a sham trainer which looks like the "real"
      trainer but is not able to produce a strengthening effect. Both groups will complete eight
      weeks of home based (real or sham) training. The sleep study will be repeated and we well
      measure any changes in measures of severity for obstructive sleep apnea.
    

Detailed description: 
      Obstructive sleep apnea (OSA) is a common disorder characterized by intermittent narrowing or
      closure of the upper airway during sleep. Loss of muscle tone with sleep onset and decreases
      in ventilatory drive following the loss of the wakefulness stimuli to breathe combine to
      result in upper airway closure in patients with structurally susceptible upper airways. We
      hypothesize that training of upper airway muscles will improve sleep apnea by augmenting the
      resting upper airway muscle tone and ability of the muscles to respond to negative
      intraluminal pressure. Training with a primitive wind instrument (such as a Digeridoo) and
      oral pharyngeal exercises (OPE) used in speech therapy have been shown to improve sleep
      apnea. Individuals who play certain types of wind instruments appear to have a lower risk of
      sleep apnea. However, to date the mechanism of improvement and the optimal method of upper
      airway training have not been well defined. We recently completed a study with a facial
      exerciser (Facial Flex) designed to improve facial muscle tone and found a decrease in
      snoring in a group with loud snoring but minimal sleep apnea. A group of UF physiologists
      (including co investigators Drs. Davenport and Silverman) have also demonstrated that brief
      periods of training with high inspiratory and/or expiratory threshold loads improved cough
      and swallowing in patients with impairment in upper airway function. Although respiratory
      pump muscles provide the driving force for pressure generation during training with pressure
      threshold loads, the upper airway muscle must maintain a patent upper airway resisting high
      negative or positive intraluminal pressures. For example, the palate must maintain a seal
      preventing air escape through the nose when high positive pressure is generated through a
      mouthpiece. Of interest a limited number of very high intensity efforts appears to be the
      optimal way to train muscles.

      We propose targeting a group of mild to moderate OSA patients (apnea-hypopnea index <
      30/hour) who are not severely obese (BMI < 35 Kg/M2) and do not have significant structural
      abnormalities of the upper airway or muscle dysfunction. We will perform a randomized
      controlled trial (training versus sham training) with 25 subjects in each treatment arm using
      two months of daily training (5 out of 7 days each week). A home sleep study (including EEG)
      will be performed before and following the training. The change in the apnea-hypopnea index
      adjusted for sleep stage and body position will be compared. Use of home sleep studies will
      dramatically reduce the cost of the study. A sleep technologist will educate subjects on
      performance of maneuvers and meet with them weekly to observe the subject's technique. A
      training log will be kept by the subjects using training schedule sheets and daily training
      will be monitored through weekly web-based communication with a study clinician.
    

Intervention name(s): Respiratory muscle strength training; Sham respiratory muscle strength training
Intervention type(s): Device; Device
Intervention description(s): Inspiratory and expiratory muscle strength training occur when subjects are required to breath in (as with inspiratory training) or out (as with expiratory training) through a pressure threshold device. This device features a spring-loaded one way valve which will only open if the subject is able to generate sufficient air pressure to overcome a predetermined pressure threshold. This threshold is typically set at 75% of the subject's maximum capacity. Repeatedly overcoming this threshold during training produces a strengthening effect in most people.; The placebo / sham intervention will mimic the active intervention(s) in every respect except the devices used will be rendered neutral via removal of the pressure threshold spring inside the devices.
Other intervention name(s): Inspiratory muscle strength training; Expiratory muscle strength training; Sham inspiratory muscle strength training; Sham expiratory muscle strength training
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Treatment
Keywords: obstructive sleep apnea; osa; breathing; snoring; respiratory; exercise; inspiratory muscle strength training; expiratory muscle strength training