Effects of Deployment Exposures on Cardiopulmonary and Autonomic Function

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.

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 exclusion criteria will be determined via self-report)