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Effects of Deployment Exposures on Cardiopulmonary and Autonomic Function

Effects of Deployment Exposures on Cardiopulmonary and Autonomic Function

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT01754922
Acronym
AirHzds
Enrollment
50
Registered
2012-12-21
Start date
2013-11-30
Completion date
2015-12-31
Last updated
2017-02-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Abnormality, Respiratory System, Autonomic Nervous System

Keywords

exercise tolerance, Veterans, operation enduring freedom, operation Iraqi freedom

Brief summary

Following deployment to Operations Enduring and Iraqi Freedom and Operation New Dawn (OEF/OIF/OND), Veterans report breathing problems, difficulty exercising and other symptoms. These symptoms may be related to deployment exposures, such as regional dust and sand, smoke from burning trash, and local industry. Studies have reported poor air quality, but very little is known about the effect that exposure to this polluted air may have on Veterans' short- and long-term health. Investigators will determine whether deployment-related exposures have affected respiratory and nervous system function in these Veterans - data that may then be used to guide rehabilitation. Ultimately, the investigators' long-term goal is to prevent the development of chronic respiratory conditions in this group of OEF/OIF/OND Veterans.

Detailed description

Evidence is clear that Veterans deployed to Operations Enduring and Iraqi Freedom and Operation New Dawn (OEF/OIF/OND) have been exposed to high levels of particulate matter (PM) that exceeded environmental, occupational and military exposure guidelines. PM exposure is acknowledged as a risk factor for cardiovascular morbidity and mortality, and can increase the risk of and exacerbate airway disease. The reviewed epidemiology indicates a high prevalence of newly reported respiratory symptoms in OEF/OIF/OND Veterans that has significantly affected their deployment duties, including their physical exertion capability. Despite these retrospective data and limited air sampling reports, prospective studies are lacking. This pilot study will evaluate cardiorespiratory and autonomic function in OEF/OIF/OND Veterans as compared to Veterans never deployed to the region. To evaluate cardiopulmonary function, each Veteran will undergo a standardized exercise challenge and bronchodilator spirometry. To evaluate autonomic nervous system function, investigators will examine indices of heart rate variability and cardiovascular reflex regulation (e.g. baroreflex sensitivity and cerebral autoregulation) during a variety of tasks. Data derived from this pilot project will yield important insight on the extent and severity of cardiorespiratory and/or autonomic impairments - data that may provide intervention points for attenuating long-term adverse outcomes such as pulmonary and cardiovascular disease. Through early identification, treatment options (e.g. exercise therapy, pharmaceutical) may be implemented to enhance physiological function, with the goal of helping to alleviate symptoms and reduce chronic disease risk.

Interventions

None listed

Sponsors

VA Office of Research and Development
Lead SponsorFED

Study design

Time perspective
CROSS_SECTIONAL

Eligibility

Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
Yes

Inclusion criteria

* Male and female Veterans between 18 - 55 years of age will be identified and screened for this study. * Two study cohorts will be recruited and attempts will be made to match group composition on age, body mass index and smoking history. * Veterans assigned to the Exposed group must have been deployed to OEF/OIF for a minimum of 90 consecutive days. * The Control group will consist of Veterans never deployed to Southwest Asia (i.e. OEF/OIF, Persian Gulf War) but were deployed during the same time period. * Each Veteran will complete a detailed exposure history questionnaire to confirm and support their group assignment.

Exclusion criteria

Participants must not meet any of the contraindications to exercise testing as described in the joint statement from the American College of Cardiology and American Heart Association. Also, individuals with history of any of the following will also be excluded: * asthma (pre-military) * cardiovascular disease * neurological impairment/disorder * pregnant * uncontrollable hypertension (SBP \> 160; DBP \> 100) * or have suffered severe/moderate traumatic brain injury within the last three years * eye/chest/abdominal surgery in last 3 months * tuberculosis exposure to self or household member * history of aneurysm or collapsed lung * history of detached retina * stroke or heart attack in the last 3 months * and history of coughing up blood in last three months (With the exception of hypertension and pregnancy (urine test), all

Design outcomes

Primary

MeasureTime frameDescription
FEV1Pre/post exercise; cross-sectionalForced expiratory volume in 1 second (FEV1) measured before and after an exercise challenge
VO2 PeakAt peak exercise; cross-sectionalMaximal oxygen consumption measured during exercise
Heart Rate VariabilityResting baseline; cross-sectionalRatio of low-frequency to high-frequency power for heart rate variability

Countries

United States

Participant flow

Participants by arm

ArmCount
Exposed
Veterans deployed to OEF/OIF/OND and environmentally exposed to high levels of particulate matter
32
Control
Veterans deployed to regions other than Iraq or Afghanistan or non-deployed
18
Total50

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyAdverse Event01

Baseline characteristics

CharacteristicExposedControlTotal
Age, Continuous34.8 years
STANDARD_DEVIATION 8.1
33.2 years
STANDARD_DEVIATION 9.7
34.6 years
STANDARD_DEVIATION 8.7
Gender
Female
6 Participants5 Participants11 Participants
Gender
Male
26 Participants13 Participants39 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
2 Participants0 Participants2 Participants
Race (NIH/OMB)
Black or African American
7 Participants14 Participants21 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
23 Participants4 Participants27 Participants
Region of Enrollment
United States
32 participants18 participants50 participants
Tobacco Pack Years1.45 Pack Years
STANDARD_DEVIATION 3.42
1.65 Pack Years
STANDARD_DEVIATION 5.2
1.5 Pack Years
STANDARD_DEVIATION 4.08

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
0 / 320 / 18
serious
Total, serious adverse events
0 / 321 / 18

Outcome results

Primary

FEV1

Forced expiratory volume in 1 second (FEV1) measured before and after an exercise challenge

Time frame: Pre/post exercise; cross-sectional

ArmMeasureGroupValue (MEAN)Dispersion
ExposedFEV1Post-Exercise FEV10.95 percentage of predicted normal valuesStandard Deviation 0.18
ExposedFEV1Pre-Exercise FEV10.94 percentage of predicted normal valuesStandard Deviation 0.16
ControlFEV1Pre-Exercise FEV11.08 percentage of predicted normal valuesStandard Deviation 0.16
ControlFEV1Post-Exercise FEV11.09 percentage of predicted normal valuesStandard Deviation 0.17
Primary

Heart Rate Variability

Ratio of low-frequency to high-frequency power for heart rate variability

Time frame: Resting baseline; cross-sectional

Population: Signal quality of the the electrocardiogram was poor for 3 individuals; therefore, their data were removed from final analysis.

ArmMeasureValue (MEAN)Dispersion
ExposedHeart Rate Variability2.02 RatioStandard Deviation 1.7
ControlHeart Rate Variability1.13 RatioStandard Deviation 1.1
Primary

VO2 Peak

Maximal oxygen consumption measured during exercise

Time frame: At peak exercise; cross-sectional

Population: 4 participants were excluded due to failure to meet maximal exercise criteria (3 from exposed, 1 from control). Therefore, we removed these individuals from the final analysis.

ArmMeasureValue (MEAN)Dispersion
ExposedVO2 Peak33.79 ml/min/kgStandard Deviation 8.6
ControlVO2 Peak34.49 ml/min/kgStandard Deviation 10.4

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026