Inspiratory Muscle Strength Training for Sleep-related Breathing Disorders

Study Overview
=================
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.

Detailed Description
-----------------
Aims of the study: To determine the influence of IMST on resting blood pressure and baroreceptor sensitivity. To determine the effect of IMST on sympathetic nervous system by measuring plasma cathecholamines and nerve recording (MSNA). Population: 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.

Official Title
-----------------
Respiratory Strength Training Mitigates Hypertension and Sleep Fragmentation in Obstructive Sleep Apnea

Conditions
-----------------
Obstructive Sleep Apnea

Intervention / Treatment
-----------------
* Other: Inspiratory muscle strength training
* Other: Placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
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

Ages Eligible for Study
-----------------
Minimum Age: 30 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional 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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: IMST Training Group<br>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<br>* Breathing training designed to augment inspiratory muscle strength, and thus targeted muscle groups may benefit from improved force generating capability result in improved breathing.<br>* Other names: IMST;|
| Placebo Comparator: Placebo Training Group<br>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<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Systolic and diastolic blood pressures (mmHg) | Blood pressure measured with blood pressure cuff and syphygmomanometer via standard auscultation technique. | Weekly blood pressure measures obtained each week for 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Apnea hypopnea index | 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. | Prior to and upon completion of the 6-weeks respiratory strength training. | 
| Sleep Quality Survey (PSQI) | 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. | Prior to and upon completion of the 6-weeks training. | 
| Plasma cathecholamines (epinephrine, norepinephrine and dopamine) | 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. | Blood draw taken prior to and upon completion of the 6-weeks respiratory strength training. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Obstructive Sleep Apnea, Inspiratory Muscle Strength Training, Baroreceptor Sensitivity, Blood Pressure