Characterizing Hypoxic Apnea Intra-individual Repeatability

NCT06399575 | Completed

• 1 other identifier: Pro00138947
• Study Type: interventional
• Target: 16
• Locations: 1 country
• Sites: 1

Brief Summary

Apneas (breath-holds) are increasingly being tested in human subjects to understand how the human body operates. Apneas decrease heart rate and increase blood pressure. These findings are driving current research into the effects of oxygen concentrations on the heart rate and blood pressure responses to apneas and the effect of breath-hold training on these responses. The interest in apnea research is three-fold:

1. 1.Apneas are a nervous system stressor that can help researchers better understand the fundamental operation of the human body;
2. 2.Elite divers can use findings from research to better their training and performance; and
3. 3.The scientific understanding of apneas may translate to a better understanding of sleep apnea.
4. 4.To provide greater certainty to previous results; and
5. 5.Inform best practices for future studies.

Conditions

Hypoxia; Apnea

Keywords

Repeatability; Reproducibility; Heart Rate

Outcome Measures

Primary Outcomes (1)

• Heart Rate

  Electrocardiogram (lead II)

  Continuous collection during both visits (2 hours on back-to-back days). Data will be extracted during free breathing (1 minute average before each apnea) and during apneas (beat-by-beat extraction from the 10 beats preceding resumption of breathing).

Secondary Outcomes (5)

• Blood Pressure

  Continuous collection during both visits (2 hours on back-to-back days). Data will be extracted during free breathing (1 minute average before each apnea) and during apneas (beat-by-beat extraction from the 10 beats preceding resumption of breathing).

• Cardiac Arrhythmias

  Continuous collection during both visits (2 hours on back-to-back days). Data will be extracted during apneas (beat-by-beat observation from the 10 beats preceding the resumption of breathing).

• Peripheral Oxygen Saturation

  Continuous collection during both visits (2 hours on back-to-back days). Data will be extracted during free breathing (1 minute average before each apnea) and during apneas (10 beats preceding the resumption of breathing to 1 minute after apnea end).

• Rating of Perceived Exertion

  Apnea (immediately following apnea)

• Apnea Duration

  Start to end of apnea: apnea start determined using cessation of flow through the pneumotachometer, apnea end determined using respiratory belt strain gauge. Estimated apnea durations are 15-30 seconds.

Other Outcomes (3)

• End-Tidal Oxygen

  Continuous collection during both visits (2 hours on back-to-back days). Data will be extracted during free breathing (1 minute average before apnea).

• End-Tidal Carbon Dioxide

  Continuous collection during both visits (2 hours on back-to-back days). Data will be extracted during free breathing (1 minute average before apnea).

• Minute Ventilation

  Continuous collection during both visits (2 hours on back-to-back days). Data will be extracted during free breathing (1 minute average before apnea).

Study Arms (1)

Apnea Following Isocapnic Hypoxia

EXPERIMENTAL

Other: Apnea Following Isocapnic Hypoxia

Interventions

Apnea Following Isocapnic Hypoxia OTHER

Decreasing end-tidal partial pressure of oxygen to 50 mmHg for five minutes, targeting 80-85% peripheral oxygen saturation. The end-tidal partial pressure of carbon dioxide will remain +1 mmHg above baseline levels. After five minutes of hypoxia, participants will complete an apnea.

Apnea Following Isocapnic Hypoxia

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Males and females between the ages of 18-70

You may not qualify if:

• Having known cardiovascular or nervous system disease
• Low or high blood pressure (\< 90/60 or \>139/85, respectively)
• Taking any prescribed medications (other than oral contraceptives) that may affect cardiovascular system function
• Females who may be pregnant (self-reported)
• Involved in other studies

Sponsors & Collaborators

• University of Alberta: lead

Study Sites (1)

University of Alberta

Edmonton, Alberta, T6G 2E1, Canada

Location

Related Publications (5)

• Busch SA, Davies H, van Diepen S, Simpson LL, Sobierajski F, Riske L, Stembridge M, Ainslie PN, Willie CK, Hoiland R, Moore JP, Steinback CD. Chemoreflex mediated arrhythmia during apnea at 5,050 m in low- but not high-altitude natives. J Appl Physiol (1985). 2018 Apr 1;124(4):930-937. doi: 10.1152/japplphysiol.00774.2017. Epub 2017 Dec 21.

  PMID: 29357505 BACKGROUND

• Busch SA, van Diepen S, Steele AR, Meah VL, Simpson LL, Figueroa-Mujica RJ, Vizcardo-Galindo G, Villafuerte FC, Tymko MM, Ainslie PN, Moore JP, Stembridge M, Steinback CD. Global REACH: Assessment of Brady-Arrhythmias in Andeans and Lowlanders During Apnea at 4330 m. Front Physiol. 2020 Jan 22;10:1603. doi: 10.3389/fphys.2019.01603. eCollection 2019.

  PMID: 32038287 BACKGROUND

• Stanforth PR, Gagnon J, Rice T, Bouchard C, Leon AS, Rao DC, Skinner JS, Wilmore JH. Reproducibility of resting blood pressure and heart rate measurements. The HERITAGE Family Study. Ann Epidemiol. 2000 Jul;10(5):271-7. doi: 10.1016/s1047-2797(00)00047-8.

  PMID: 10942874 BACKGROUND

• Hopkins WG. Measures of reliability in sports medicine and science. Sports Med. 2000 Jul;30(1):1-15. doi: 10.2165/00007256-200030010-00001.

  PMID: 10907753 BACKGROUND

• Weir JP. Quantifying test-retest reliability using the intraclass correlation coefficient and the SEM. J Strength Cond Res. 2005 Feb;19(1):231-40. doi: 10.1519/15184.1.

  PMID: 15705040 BACKGROUND

MeSH Terms

Conditions

Hypoxia; Apnea

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Respiration Disorders; Respiratory Tract Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 21, 2024
• First Posted: May 6, 2024
• Study Start: May 2, 2024
• Primary Completion: June 28, 2024
• Study Completion: June 28, 2024
• Last Updated: July 3, 2024

Record last verified: 2024-07

Locations

CA (1)