This section covers respiratory outcomes according to the major types of studies published in the Gulf War literature: respiratory outcomes in deployed vs nondeployed personnel without regard to specific exposures, and respiratory outcomes in relation to two types of exposures: to oil-well fires and to nerve agents. Table 5.14 contains a summary of all the studies reviewed in this section.
Two publications reported on respiratory outcomes among participants in the medical evaluation component (phase III) of the large, population-based VA study (Eisen et al. 2005; Karlinsky et al. 2004). Eisen and colleagues (2005) evaluated 1,061 Gulf War and 1,128 non-Gulf War veterans who had been randomly selected from 11,441 Gulf War-deployed and 9,476 Gulf War-nondeployed veterans who previously had participated in a 1995 questionnaire survey (Kang et al. 2000). No statistically significant increase in the prevalence of self-reported asthma, bronchitis, or emphysema was observed among deployed veterans in models that adjusted for smoking and demographic variables (adjusted OR 1.07, 95% CI 0.65-1.77, for the three diseases combined). Obstructive lung disease was defined by the investigators as a history of lung disease (asthma, bronchitis, or emphysema) or pulmonary symptoms (wheezing, dyspnea on exertion, or persistent coughing with phlegm), and either the use of bronchodilators or at least 15% improvement in FEV15 after use of a short-acting bronchodilator. No increase in obstructive lung disease was observed among deployed personnel (adjusted OR 0.91, 95% CI 0.52-1.59). Limitations of the study include potential selection bias owing to low participation rates – 53% and 39% of deployed and nondeployed veterans, respectively.
Karlinsky and colleagues (2004) reported on results of pulmonary function tests (PFTs) on the same VA population that Eisen and colleagues studied. PFT results were classified into five categories: normal pulmonary function, nonreversible airway obstruction, reversible airway obstruction, restrictive lung physiology, and small airway obstruction. The patterns of PFT results were similar in deployed and nondeployed veterans; there were no statistically significant differences. The pattern of PFT results was also reported to be similar in those exposed and those not exposed on the basis of DOD exposure estimates developed in 2002 (see Chapter 2), of exposure to nerve agents through destruction of munitions at the storage site at Khamisiyah in 1991. Prevalences of self-reported pulmonary symptoms were higher in deployed veterans; however, self-reported diagnoses, use of asthma medications, and self-reported physician visits and hospitalizations for pulmonary conditions were similar in deployed and nondeployed. Although no adjustments were made for covariates, demographic variables were similar in the two groups and a history of tobacco-smoking was more common in deployed veterans than in nondeployed veterans (51% vs 44%, p = 0.03). Limitations include the inadequacy of the sampling strategy description to evaluate bias and no explanation of “matching” in the analysis.