Cardiovascular Effects of Exposure to Wood Smoke in Healthy Human Adults

NCT04297761 | Suspended

• 1 other identifier: 19-2078
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

MASKOFF Clinical Trials 8/22/23 Brief Summary: Purpose: The study is designed to investigate cardiovascular effects of young healthy human subjects exposed to wood smoke. Participants: Approximately 80 young (18-35 years old) healthy subjects to complete. Procedure (methods): After consenting to participate in the study, subjects will be exposed first to filtered air and on the next exposure day to approximately 500 µg/m\^3 wood smoke. Both exposures will be 2 hours long with alternating 15 min of exercise (cycle ergometer) and 15 min rest period. The exercise level will be adjusted to achieve approximately 20 L/min/m\^2 minute ventilation. Venous blood samples and measurements of lung, cardiac and vascular function will be made prior to and immediately following each exposure. Induced sputum samples and nasal epithelial lining fluid will be collected approximately 24 hours post each exposure.

Conditions

Healthy

Keywords

Healthy subjects; Wood smoke; Respiratory effects; Cardiovascular effects; Young

Outcome Measures

Primary Outcomes (1)

• Change in polymorphonuclear neutrophils (PMN%) in the Sputum

  Airway inflammation will be assessed by the % PMN in the sputum

  Day 1, Day 3, Day 5

Secondary Outcomes (9)

• Change in Forced Expired Volume in the First Second (FEV1) (liter)

  Day 1, Day 2, Day 3, Day 4, Day 5

• Change in Forced Vital Capacity (FVC) (liter)

  Day 1, Day 2, Day 3, Day 4, Day 5

• Change in Diameters (mm) of Retinal Arteries and Veins

  Day 2, Day 3, Day 4, Day 5

• Percent Change in Heart Rate Variability

  Day 2, Day 3, Day 4, Day 5

• Change in Blood Fatty Acids (ng/mL)

  Day 2, Day 3, Day 4, Day 5

Study Arms (1)

Controlled Exposure

EXPERIMENTAL

All subjects will be exposed to both air containing wood smoke and filtered air for 2 hours with alternating 15 minutes of exercise (cycle ergometer) and rest.

Other: Filtered Air; Other: Wood Smoke

Interventions

Filtered Air OTHER

Ambient air will be filtered and used for control exposure.

Controlled Exposure

Wood Smoke OTHER

Wood smoke is generated by smoldering dry white oak logs and the exposure level will be maintained at an average of 500 µg/m\^3 for 2 hours.

Controlled Exposure

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age 18-35 years old , healthy, with a Body Mass Index (BMI, kg/m\^2) values ≥ 19 and ≤ 34, inclusive).
• Physical conditioning that allows intermittent, mild exercise for approximately 60 min during a 2 hour exposure session. The volunteer must be able to complete the exposure exercise regimen at a workload sufficient to induce a minute ventilation rate of approximately 20 L/min/m\^2 for 15 min without exceeding 80% of projected maximal heart rate.
• Normal ECG.
• Normal lung function based on NHANES III reference values. i. Forced vital capacity (FVC) ≥ 80% of that predicted for age, gender, ethnicity, and height.
• ii. Forced expiratory volume in one second (FEV1) ≥ 80% of that predicted for age, gender, ethnicity, and height.
• iii: FEV1/FVC ratio ≥ 70% (absolute value)
• Oxygen saturation greater than 94% at the time of physical exam.

You may not qualify if:

• Individuals with the following conditions:
• A history of acute or chronic cardiovascular disease, chronic respiratory disease, cancer, rheumatologic disease, neuromuscular disease, or immunodeficiency state.
• BMI (kg/m\^2) values \< 19 and \> 34.
• Blood pressure readings ≥ 140 systolic and/or ≥ 90 diastolic.
• Diabetes (previously diagnosed or with hemoglobin A1c level equal to or greater than 6.4%).
• Asthma or a history of asthma.
• Bleeding/clotting disorders.
• Individuals with a cardiovascular disease risk score greater than 10% using the ACC/AHA ASCVD risk calculator. (Based on the 10-year risk of heart disease or stroke using the Atherosclerotic Cardiovascular Disease algorithm published in 2013 American College of Cardiology/American Heart Association Guideline on the Assessment of Cardiovascular risk.)
• Individuals who have had recent (within 6 months) abdominal an/or eye surgery, or with any types of hernia, as well as any other contraindicators for raised intra-abdominal pressure.
• Individuals who are currently taking systemic steroids or oral anticoagulants long term.
• Individuals who are allergic to:
• Chemical vapors or gases.
• Tape or electrodes on their skin.
• Or individuals with active allergies or currently experience allergy related symptoms
• Individuals who are pregnant, attempting to become pregnant or breastfeeding.

Sponsors & Collaborators

• University of North Carolina, Chapel Hill: lead
• Environmental Protection Agency (EPA): collaborator

Study Sites (1)

U.S. Environmental Protection Agency Human Studies Facility

Chapel Hill, North Carolina, 27514, United States

Location

Study Officials

• James Samet, PhD

  Environmental Protection Agency (EPA)

  PRINCIPAL INVESTIGATOR

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: February 27, 2020
• First Posted: March 5, 2020
• Study Start: May 25, 2021
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: June 12, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF
• Time Frame: The data will be available to the public after the conclusion of the study and the publication of the manuscripts.
• Access Criteria: Data will be available at the U.S. EPA Science Hub.

Locations

US (1)