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

Summary: 
      Obstructive sleep apnea (OSA) carries serious health consequences for patients. Evidence
      exists that some behavioral (e.g. exercise based) therapies may assist in lessening the
      severity of this disorder. The proposed investigation will examine the effects of eight weeks
      of genioglossus muscle strength training on measures of snoring and OSA severity as well as
      genioglossus protrusive muscle strength.
    

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. The
      genioglossus (GG, tongue) muscle plays an important role in maintaining upper airway patency.
      The GG is responsible for tongue protrusion and stiffens the tongue and prevents posterior
      tongue displacement and upper airway closure. The GG is a phasic respiratory muscle. One can
      demonstrate inspiratory bursts in GG EMG activity slightly preceding the onset of inspiratory
      activity of respiratory pump muscles. The inspiratory bursts of GG activity also increase in
      response to negative pressure in the upper airway to help maintain upper airway patency. In
      some OSA patients this response is blunted. While one study did not find a difference in
      protrusion muscle strength between a group of OSA patients (apnea hypopnea index, AHI =
      20/hour) and normal controls (Mortimore et al) there was wide variability in muscle strength
      at similar AHI values. Another study (Oh et al) did find a correlation between tongue
      protrusion strength and the apnea index (lower strength, higher apnea index). It is
      hypothesized that strength training of the GG will reduce snoring and sleep apneas by
      augmenting the resting GG tone and enhancing the ability of the muscle to respond to negative
      upper airway pressure. Training of upper airway muscles including the tongue is often used in
      rehabilitation of patients with prior cerebrovascular accidents or damage due to surgical
      resection for cancer. Typically, the patient presses the tongue against the back of the upper
      teeth (direction both upward and forward). However, it is believed that tongue protrusion is
      best trained by active forward protrusion of the tongue between the teeth under load. To
      facilitate GGs training participants will push a spring loaded piston forward with the
      tongue. The piston fits inside an outer chamber. The piston can also be connected to a force
      measuring device to estimate protrusive tongue force.

      Two groups of participants will be examined: Group 1: primary snoring and Group 2: mild to
      moderate OSA patients (apnea-hypopnea index < 30/hour) who are not severely obese (BMI < 40
      Kg/M2) and do not have significant structural abnormalities of the upper airway or muscle
      dysfunction. This preliminary investigation consists of a randomized controlled trial
      (training versus sham training) with 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 training maneuvers and meet with
      them weekly to observe the subject's technique and measure tongue strength. A training log
      will be kept by the subjects using training schedule sheets and training will be directly
      monitored at least 2 times weekly through with a study clinician (electronically via
      facetime, skype or by direct observation).
    

Intervention name(s): Genioglossis Strength Trainer; Placebo Genioglossis Strength Trainer
Intervention type(s): Device; Device
Intervention description(s): The genioglossis strength trainer is a handheld device, manufactured in house, consisting of an outer tube, inner piston, and pressure loaded spring. The device can be set to a specific pressure resistance ranging from 10 to 40 Newtons. Users press against the inner piston with their tongues until the piston moves approximately 1/2 centimeter (and the inner pressure loaded spring depresses approximately 1/2 centimeter).; The placebo genioglossis strength trainer is a handheld device, manufactured in house, consisting of an outer tube, inner piston, and pressure loaded spring. Whereas the pressure loaded spring in the active trainer can be set to a wide range of pressures, the placebo trainer has a maximum resistance of 5 Newtons. The device is set to a specific pressure resistance of 5 Newtons at all times. Users press against the inner piston with their tongues until the piston moves approximately 1/2 centimeter (and the inner pressure loaded spring depresses approximately 1/2 centimeter).
Other intervention name(s): Tongue Strength Trainer; Placebo Tongue Strength Trainer
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Device Feasibility