Acute Intermittent Hypoxia and Breathing in Neuromuscular Disease (AIH-ALS)

This project seeks to investigate the effects of a single acute intermittent hypoxia (AIH) session on respiratory and non-respiratory motor function and EMG (electromyography) activity on patients with ALS (amyotrophic lateral sclerosis) and healthy controls.

Study Overview

• Status: Completed
• Conditions: Neuromuscular Diseases; Amyotrophic Lateral Sclerosis (ALS)
• Intervention / Treatment: Other: Acute Intermittent Hypoxia; Other: Sham Acute Intermittent Hypoxia

Detailed Description

Most ALS patients survive less than 5 years after diagnosis, and the main cause of death is respiratory failure. The investigators are interested in the therapeutic potential of acute intermittent hypoxia (AIH) for individuals with neuromuscular diseases, such as ALS. More than two decades of research indicates AIH elicits meaningful respiratory and non-respiratory motor recovery. Acute intermittent hypoxia (AIH) consists of alternating periods of breathing mildly hypoxic (lowered oxygen concentration) and normoxic (normal oxygen concentration) air.

The investigators propose to study mechanisms of respiratory plasticity associated with a single presentation of mild AIH. The fundamental hypothesis guiding this proposal is that even a single AIH trial improves respiratory (and non-respiratory) motor function in ALS patients procedure. Participants will then be asked to breathe air with reduced oxygen for short periods of time, for a duration of 45 minutes. The activity of your muscles and your heart function will be monitored throughout the procedure.

• Study Type: Interventional
• Enrollment (Actual): 29
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Florida
    • Gainesville, Florida, United States, 32611
      • University of Florida
    • Gainesville, Florida, United States, 32610
      • UF Clinical Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• a healthy adult
• clinical diagnosis of ALS
• baseline FVC >60% predicted for age, sex and height.

Exclusion Criteria:

• pregnant
• diagnosed cardiovascular disease
• a BMI >35 kg/m2
• currently take selective serotonin reuptake inhibitors (SSRI)
• history of seizures
• history of hospitalization for sepsis
• respiratory infection or took antibiotic medications within the past 4 weeks
• use external respiratory support during any waking hours
• participate in a pharmaceutical trial to treat ALS
• have any other medical condition the PI or medical director identify would make it unsuitable to participate.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ALS Group; Participants will complete a single 45 minute session of acute intermittent hypoxia (AIH), as well as, the 45 minute sham AIH session, consisting of breathing air with normal oxygen levels. Breathing, muscle activity and heart activity will be monitored before, during and after both procedures.	Other: Acute Intermittent Hypoxia; AIH entails continuous breathing as the level of oxygen in the air is decreased, then returned to normal. Participants will alternate between breathing normal air and breathing hypoxic air (air that has less oxygen). Participants will complete a single 45 minute session of acute intermittent hypoxia (AIH). Breathing, muscle activity and heart activity will be monitored before, during and after the procedure. The intervals will last 1 minute each.; Other Names: AIH; Other: Sham Acute Intermittent Hypoxia; Participants will complete the sham acute intermittent hypoxia, consisting of a single 45 minute session of breathing air with normal oxygen levels. All aspects of this procedure will otherwise be the same as for the AIH procedure. Breathing, muscle activity and heart activity will be monitored before, during and after the procedure.; Other Names: Sham AIH
Experimental: Healthy Control Group; Participants will complete a single 45 minute session of acute intermittent hypoxia (AIH), as well as, the 45 minute sham AIH session, consisting of breathing air with normal oxygen levels. Breathing, muscle activity and heart activity will be monitored before, during and after both procedures.	Other: Acute Intermittent Hypoxia; AIH entails continuous breathing as the level of oxygen in the air is decreased, then returned to normal. Participants will alternate between breathing normal air and breathing hypoxic air (air that has less oxygen). Participants will complete a single 45 minute session of acute intermittent hypoxia (AIH). Breathing, muscle activity and heart activity will be monitored before, during and after the procedure. The intervals will last 1 minute each.; Other Names: AIH; Other: Sham Acute Intermittent Hypoxia; Participants will complete the sham acute intermittent hypoxia, consisting of a single 45 minute session of breathing air with normal oxygen levels. All aspects of this procedure will otherwise be the same as for the AIH procedure. Breathing, muscle activity and heart activity will be monitored before, during and after the procedure.; Other Names: Sham AIH

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent Change in Maximal Inspiratory Pressure (MIP)	MIP is a maximal voluntary static contraction of the inspiratory muscles against a closed valve, measured at the mouth. The test will be repeated until 3 measurements are obtained within 10% variability and an average of the three trials is reported. The change in MIP will be the percent difference in pressure between the averaged baseline MIP and the averaged follow-up measure, which is tested 60 minutes after the gas intervention.	3 Hours
Percent Change in Maximal Voluntary Grip Force	Maximal static voluntary handgrip contractions will be evaluated in a seated position with the arm at the side and elbow flexed to 90 degrees. The test will be repeated until 3 measurements are obtained within 10% variability and then averaged. The change in grip will be the percent difference in force between the averaged baseline grip and the averaged follow-up grip measure, which is tested 60 minutes after the gas intervention.	3 Hours
Percent Change in Sniff Nasal Inspiratory Pressure	Maximal voluntary contractions of the inspiratory muscles measured with a pressure sensor placed in the nare. The test will be repeated until 3 measurements are obtained within 10% variability and then averaged. The change in sniff nasal inspiratory pressure will be the percent difference in pressure between the averaged baseline sniff nasal inspiratory pressure and the averaged follow-up measure, which is tested 60 minutes after the gas intervention.	3 Hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent Change in Minute Ventilation	Minute ventilation is measured using a pneumotachograph connected to the face mask to record breath-by-breath volume and breathing rate, which is then multiplied to calculate minute ventilation. After achieving a stable tidal volume, 5 minutes of resting minute ventilation will be recorded and then averaged. The change in minute ventilation will be the percent difference in volume between the averaged baseline ventilation and the averaged follow-up ventilation, which is tested 60 minutes after the gas intervention.	3 Hours
Occlusion Pressure (P0.1)	P0.1 is measured with a pressure transducer connected to a face mask and represents the pressure generated against a transiently occluded airway in the first 0.1 sec of inspiration. The generated during this initial period of inspiration is resistant to learning or sensory bias and is considered a clinical estimate of inspiratory drive. Five measurements will be conducted and then averaged, with 5-15 un-occluded breaths between each P0.1 measurement. The averaged pressures at baseline and 60 minutes post-gas intervention will be reported and will be expressed in cm H2O.	3 Hours
Percentage Change in Respiratory EMG Vector Magnitude	EMG vector magnitude represents the composite surface EMG activity expressed from eight respiratory muscles (bilateral scalene, sternocleidomastoid, 2nd parasternal, and 8th external intercostal/diaphragm). The vector magnitude was calculated for each participant from the root mean square (RMS) values from each EMG channel, as the square root of the sum of the individual squared EMG channel amplitudes.	3 Hours

Collaborators and Investigators

• Sponsor: University of Florida
• Investigators: Principal Investigator: Barbara K Smith, PT, PhD, University of Florida

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2018
• Primary Completion (Actual): June 2, 2023
• Study Completion (Actual): June 2, 2023

Study Registration Dates

• First Submitted: August 22, 2018
• First Submitted That Met QC Criteria: August 22, 2018
• First Posted (Actual): August 24, 2018

Study Record Updates

• Last Update Posted (Actual): May 15, 2025
• Last Update Submitted That Met QC Criteria: May 14, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: hypoxia; normoxia; acute intermittent hypoxia (AIH); respiratory motor function; EMG (electromyography)
• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Metabolic Diseases; Neurodegenerative Diseases; Signs and Symptoms, Respiratory; Spinal Cord Diseases; TDP-43 Proteinopathies; Proteostasis Deficiencies; Hypoxia; Motor Neuron Disease; Amyotrophic Lateral Sclerosis; Neuromuscular Diseases
• Other Study ID Numbers: IRB201801131; OCR18018 (Other Identifier: OnCore)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No