Circadian Rhythm Disruption Effects on Smoke Inhalation

NCT04955431 | Completed Results

• 1 other identifier: IRB# is 83-21
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

Particulate matter exposure during smoke inhalation provokes inflammatory immune responses in people exposed to burning biomass including fire fighters and civilians. Persistent occupational exposure to particulate matter represents a unique hazard for firefighters, underpinning a burgeoning research area. This trial will evaluate the effects of sleep deprivation and circadian rhythm disruption on the inflammatory response to woodsmoke associated particulate matter exposure. Participants will undergo 2 experimental trials in a randomized cross-over design. Participants will have either an 8-hour sleep opportunity or a 4-hour sleep opportunity prior to reporting to lab for a 45 minute simulated firefighting trial (wood smoke associated particulate matter filtered to 2.5 um at a concentration of 250 ug/m\^3, while exercising at a moderate intensity). The effects of sleep restriction and simulated firefighting will be measured.

Conditions

Inflammation; Sleep Deprivation; Circadian Rhythm Sleep Disorder, Shift Work Type; Smoke Inhalation

Outcome Measures

Primary Outcomes (1)

• Blood Inflammation

  IL-6 will be measured in the plasma

  samples collected at baseline, immediately post exposure

Secondary Outcomes (1)

• Exhaled Breath Condensate Pentraxin-3

  samples collected at baseline, immediately post exposure

Study Arms (2)

Normal Sleep (with 250 ug/m^3 PM2.5)

PLACEBO COMPARATOR

Participants will have a normal sleep opportunity the night prior to reporting to the lab for the simulated firefighting session (250 ug/m\^3 PM2.5 with moderate intensity exercise).

Behavioral: Normal Sleep

Restricted Sleep (with 250 ug/m^3 PM2.5)

EXPERIMENTAL

Participants will have a restricted sleep opportunity (\~4 hours) the night prior to reporting to the lab for the simulated firefighting session (250 ug/m\^3 PM2.5 with moderate intensity exercise).

Behavioral: Sleep Restriction

Interventions

Sleep Restriction BEHAVIORAL

Participants will be allowed \~4 hour sleep opportunity during the restricted night of sleep prior to reporting to lab for a simulated firefighting session.

Also known as: Circadian Rhythm Disruption, SR

Restricted Sleep (with 250 ug/m^3 PM2.5)

Normal Sleep BEHAVIORAL

Participants will be allowed \~8 hour sleep opportunity the night of sleep prior to reporting to lab for a simulated firefighting session.

Also known as: NS

Normal Sleep (with 250 ug/m^3 PM2.5)

Eligibility Criteria

• Age: 18 Years - 44 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy
• Male
• years of age

You may not qualify if:

• Preexisting cardiometabolic and/or pulmonary diseases
• Preexisting sleep disorder
• Smoking (current or within last year)

Sponsors & Collaborators

• University of Montana: lead
• University of Nevada, Las Vegas: collaborator

Study Sites (1)

School of Integrative Physiology and Athletic Training

Missoula, Montana, 59812, United States

Location

MeSH Terms

Conditions

Inflammation; Sleep Deprivation; Sleep Disorders, Circadian Rhythm; Smoke Inhalation Injury

Condition Hierarchy (Ancestors)

Pathologic Processes; Pathological Conditions, Signs and Symptoms; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Neurologic Manifestations; Signs and Symptoms; Mental Disorders; Chronobiology Disorders; Occupational Diseases; Burns, Inhalation; Burns; Wounds and Injuries

Limitations and Caveats

Our study was limited by a smaller sample size than we had anticipated.

Results Point of Contact

• Title: Dr. John Quindry
• Organization: University of Montana

john.quindry@mso.umt.edu

406-243-4268

Study Officials

• John C Quindry, PhD

  University of Montana

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor and Chair

Model Details: Randomized cross-over design

Study Record Dates

• First Submitted: June 21, 2021
• First Posted: July 8, 2021
• Study Start: January 24, 2022
• Primary Completion: March 17, 2022
• Study Completion: April 17, 2022
• Last Updated: May 30, 2025
• Results First Posted: May 30, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)