By Brenda L. Mooney
SAN DIEGO ─ Veterans returning from Iraq/Afghanistan and the Gulf War with pulmonary function abnormalities have a significantly greater risk of developing chronic respiratory disease years later, according to a new study presented at the 2014 American Thoracic Society International Conference in San Diego.1
“Previous studies of Gulf War and Iraq/Afghanistan veterans have found persistent respiratory symptoms decades after their deployment but have not always detected clinically significant pulmonary abnormalities,” said lead author Michael Falvo, PhD, a research physiologist at the VA’s War Related Illness and Injury Study Center. “In our study, however, we found evidence of small airway obstruction and other pulmonary abnormalities in many deployed veterans.”
Asthma, chronic obstructive pulmonary disease and other respiratory issues can stem from small airway obstruction.
The study was a departure from previous research in both U.S. and Australian 1991 Gulf War veterans which observed no clinically significant pulmonary abnormalities in deployed veterans despite the presence of symptoms that persist even 20 years later.
Increased respiratory symptom reporting up to 10 years post-deployment also has been an issue among Iraq and Afghanistan veterans (IAV), leading researchers to compare patterns of pulmonary function abnormalities in Gulf War and IAV veterans evaluated at a post-deployment tertiary-care clinic in comparison to a previously published population-based sample of Gulf War veterans evaluated 10 years post-deployment.
The earlier study found identical pulmonary function test results among deployed and nondeployed Gulf War veterans.2
“Our findings did not confirm the hypothesis that deployment to the Gulf War in 1990-91 resulted in increased prevalence of clinically significant pulmonary abnormalities 10 years later, wrote the authors led by Joel B. Karlinsky, MD, of the Boston VAMC and Boston University.
For the recently presented retrospective study, researchers tracked 63 Gulf War veterans approximately 20 years post-deployment and 70 Iraq/Afghanistan veterans about 10 years post-deployment. Study subjects were classified as follows: 1) Normal Pulmonary Function (NPF); 2) Non-Reversible Airway Obstruction (NRAO); 3) Reversible Airway Obstruction (RAO); 4) Restrictive Lung Physiology (RLP); and 5) Small Airway Obstruction (SAO). Categories and prediction equations from the Karlinsky study were used for consistency.
With pulmonary function abnormalities assessed using spirometry, the newer study found that small airway obstruction was five times greater — 38% vs. 7% — and the rate of restrictive lung physiology was twice as much — 24% vs. 12% — among Gulf War veterans compared with a reference group from an earlier population-based sample of Gulf War veterans evaluated 10 years post-deployment. In the Iraq/Afghanistan veterans, meanwhile, the rate of small airway obstruction was also five times greater, 31% vs. 7%, but rates of nonreversible airway obstruction were significantly lower in the study groups than in the reference sample.
“Our findings are generally consistent with previous studies demonstrating NPF in the majority of Gulf War and IAV veterans,” according to Falvo’s presentation. “However, veterans evaluated at our post-deployment health clinic approximately 20 (Gulf War) and 10 (IAV) years post-deployment demonstrate unique spirometry patterns.”
He called for confirmation of the spirometry patterns in larger population-based samples, adding that “high rates of SAO in our sample, particularly for younger veterans, warrant further attention as this pattern may indicate a higher risk of progression to chronic respiratory disease.”
If confirmed in larger studies, Falvo explained, the VA could use the patterns to determine which veterans might require earlier intervention.
“Our laboratory is currently engaged in multiple studies, supported by the Department of Veterans Affairs, to better understand mechanisms of respiratory symptoms in deployed veterans,” he added.
What might have caused pulmonary function abnormalities in veterans serving in Iraq and Afghanistan remains a matter of debate. A VA-commissioned report from the Institute of Medicine in late 2011 concluded that it could not say whether troops’ exposures to emissions from open-air burn pits caused ongoing health effects. The report left open the possibility that the burn pits or other sources of air pollution were the cause of respiratory problems in deployed troops.
Among the reasons for the IoM’s inconclusive results were “insufficient data” on troops’ exposures to open-air burn pits as well as high background levels of ambient pollution from other sources and lack of information on the quantities and composition of wastes burned in the pits, all of which “complicate interpretation of the data,” according to the authors.
Respiratory symptoms are recognized as a marker of chronic multi-symptom illness (CMI), also called Gulf War Illness. CMI is defined by the presence of chronic symptoms in more than one of six categories: fatigue, mood and cognition, musculoskeletal, gastrointestinal, respiratory and neurologic.
Recently, the Research Advisory Committee (RAC) on Gulf War Illnesses reported that exposures to pesticides and pyridostigmine bromide are causally associated with Gulf War illness.
“Gulf War illness is a serious physical disease, affecting at least 175,000 veterans of the 1990-1991 Gulf War that resulted from hazardous exposures in the Gulf War theater,” that report stated.
1Falvo MJ, Osinubi O, Klein JC et al. Durbin D, Kallan M, Elliott M. Late Prevalence of Pulmonary Function Abnormalities In Iraq/Afghanistan Veterans. Paper presented at: 2014 American Thoracic Society International Conference. May 2014; San Diego.
2Karlinsky JB, Blanchard M, Alpern R, Eisen SA, Kang H, Murphy FM, Reda DJ. Late prevalence of respiratory symptoms and pulmonary function abnormalities in Gulf War I Veterans. Arch Intern Med. 2004 Dec 13-27;164(22):2488-91. PubMed PMID: 15596641