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Inspiratory Muscle Strength Training for Sleep-related Breathing Disorders

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02709941
Recruitment Status : Completed
First Posted : March 16, 2016
Last Update Posted : November 29, 2017
American Heart Association
Information provided by (Responsible Party):
E. Fiona Bailey,PhD, University of Arizona

Brief Summary:
The purpose of the current study is to investigate the effects of a novel breathing training, called inspiratory muscle strength training (IMST), on sleep patterns, breathing and blood pressure for patients diagnosed with mild, moderate and severe sleep apnea.

Condition or disease Intervention/treatment Phase
Obstructive Sleep Apnea Other: Inspiratory muscle strength training Other: Placebo Not Applicable

Detailed Description:

Aims of the study:

  1. To determine the influence of IMST on resting blood pressure and baroreceptor sensitivity.
  2. To determine the effect of IMST on sympathetic nervous system by measuring plasma cathecholamines and nerve recording (MSNA).


30 subjects aged 30-75 years, who have previously been diagnosed with obstructive sleep apnea, as defined by the National Institutes of Health (National Heart Lung, and Blood Institute) will be included in this study.

Study Protocol:

  • Pre-training assessment and overnight sleep study
  • 5-10 minutes each day breathing training (IMST) at home using a hand-held device for 6 weeks
  • Once weekly laboratory visit
  • Post-training assessment and overnight sleep study

Pre- and post-training assessment include blood pressure measurement, body weight, neck circumference, cardiorespiratory monitoring, nerve recording, blood draw and sleep surveys.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 25 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: the subjects were randomly allocated to either the sham training group or the inspiratory muscle training group using randomization lists for 4 strata (male/female X young/old)
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Respiratory Strength Training Mitigates Hypertension and Sleep Fragmentation in Obstructive Sleep Apnea
Study Start Date : March 2016
Actual Primary Completion Date : October 2017
Actual Study Completion Date : October 2017

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Sleep Apnea

Arm Intervention/treatment
Active Comparator: IMST Training Group
Subjects in inspiratory muscle strength training group will complete 30 breaths against a resistance set at 75% of Maximal Inspiratory Pressure (PI Max) everyday for period of 6 weeks.
Other: Inspiratory muscle strength training
Breathing training designed to augment inspiratory muscle strength, and thus targeted muscle groups may benefit from improved force generating capability result in improved breathing.
Other Name: IMST

Placebo Comparator: Placebo Training Group
Subjects in placebo training group will complete 30 breaths against a resistance set at 15% of Maximal Inspiratory Pressure (PI Max) everyday for period of 6 weeks.
Other: Placebo

Primary Outcome Measures :
  1. Systolic and diastolic blood pressures (mmHg) [ Time Frame: Weekly blood pressure measures obtained each week for 6 weeks ]
    Blood pressure measured with blood pressure cuff and syphygmomanometer via standard auscultation technique.

Secondary Outcome Measures :
  1. Apnea hypopnea index [ Time Frame: Prior to and upon completion of the 6-weeks respiratory strength training. ]
    Documentation of the total number of apneas and hypopneas experienced by the individuals per hour of sleep and expressed as the apnea-hypopnea index or AHI which has the following ranges; <5 normal; 5-15 mild, 15-30 moderate and >30 severe AHI.

  2. Sleep Quality Survey (PSQI) [ Time Frame: Prior to and upon completion of the 6-weeks training. ]
    This is a rating scale of overall sleep quality ranging from 0-21 with values <5 rated as indicative of normal or good sleep quality and a score of 21 indicative of most severe sleep disturbance.

  3. Plasma cathecholamines (epinephrine, norepinephrine and dopamine) [ Time Frame: Blood draw taken prior to and upon completion of the 6-weeks respiratory strength training. ]
    Plasma catecholamines are determined via morning blood draw taken after 20 minutes supine rest. Reference ranges for plasma catecholamines are as follows: plasma epinephrine is 10-200 pg/ml; plasma norepinephrine 80-250 pg/ml and plasma dopamine 0-20 pg/ml.

Information from the National Library of Medicine

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Ages Eligible for Study:   30 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age 30-75 years
  • Diagnosed with Obstructive Sleep Apnea with Apnea Hypopnea Index (AHI) > 15
  • Neck circumference > 16 cm

Exclusion Criteria:

  • Body mass index (BMI) > 40kg/m2
  • Implanted pacemaker
  • On anticoagulant medication
  • On hypnotic medication
  • On immunosuppressive medication
  • Acute or recent (3 months prior to study) infection
  • History of hypothyroidism
  • History of stroke or neuromuscular disease
  • Moderate to severe heart failure
  • Severe ischemic heart disease
  • Severe obstructive and restrictive lung disease
  • Cor pulmonale
  • Cognitive disorders
  • Obstructive nasal disease or history of spontaneous pneumothorax or rib fracture
  • History of neurological, respiratory, head /neck, or thoracic surgery

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02709941

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United States, Arizona
Department of Physiology at the University of Arizona
Tucson, Arizona, United States, 85721
Sponsors and Collaborators
University of Arizona
American Heart Association
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Principal Investigator: E. Fiona Bailey, Ph.D. University of Arizona
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Responsible Party: E. Fiona Bailey,PhD, Associate Professor, University of Arizona Identifier: NCT02709941    
Other Study ID Numbers: 16GRNT26700007
First Posted: March 16, 2016    Key Record Dates
Last Update Posted: November 29, 2017
Last Verified: November 2017
Keywords provided by E. Fiona Bailey,PhD, University of Arizona:
Obstructive Sleep Apnea
Inspiratory Muscle Strength Training
Baroreceptor Sensitivity
Blood Pressure
Additional relevant MeSH terms:
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Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases