Kelsall et al. (2004b) reported respiratory outcomes from a cross-sectional study of Australian Gulf War veterans. The gulf-deployed cohort comprised 1,456 participants and the nongulf military cohort included 1,588 participants. Response rates differed greatly between deployed (80.5%) and nondeployed (56.8%). Deployed veterans reported higher prevalences of all respiratory symptoms and some self-reported symptom-based respiratory diagnoses. Lung function measures adjusted for smoking and other covariates were somewhat higher in the deployed group (for example, FEV1/FVC% <70%; OR 0.8, 95% CI 0.5-1.1). FVC6, but not FEV1, was associated with self-report of exposure to oil-fire smoke. Although generally well conducted, the study was limited by the potential for selection bias, the lack of doctor-diagnosed respiratory conditions, and, with respect to effects of exposure to oil-fire smoke, the lack of availability of modeled exposure estimates.
Gray and colleagues (1999a) enrolled 1,497 study subjects from 14 Seabee commands in the US Navy, 527 of whom were Gulf War veterans and 970 were nondeployed veterans. Although respiratory symptoms were reported more frequently by the Gulf War veterans, pulmonary function measures adjusted for age, height, race, and smoking status were not associated with Gulf War status (mean FVC: Gulf War 4.96 L, non-Gulf War 4.99 L, p = 0.77; mean FEV1: Gulf War 4.05 L, non-Gulf War 4.04 L, p = 0.81).
A cross-sectional study of military personnel from Denmark, involved primarily in peacekeeping or humanitarian roles after the end of the Gulf War, also found increased respiratory symptoms among gulf-deployed personnel (n = 686) compared with nondeployed (n = 231) but no statistically significant differences in pulmonary function (FVC percent of expected: Gulf War 100.7, non-Gulf War 100.7; FEV1 percent of expected: Gulf War 95.6, non-Gulf War 96.4). Smoking patterns were very similar in the two groups (Ishoy et al. 1999b).
The overwhelming majority of secondary studies conducted among Gulf War veterans have found that several years after deployment veterans report higher levels of respiratory symptoms and of respiratory illnesses than nondeployed troops whether from the United States (Doebbeling et al. 2000; Gray et al. 2002; Iowa Persian Gulf Study Group 1997; Kang et al. 2000; Karlinsky et al. 2004; Kroenke et al. 1998; Petruccelli et al. 1999; Steele 2000), the UK (Cherry et al. 2001b; Nisenbaum et al. 2004; Simmons et al. 2004; Unwin et al. 1999), Canada (Goss Gilroy Inc. 1998), Australia (Kelsall et al. 2004b), or Denmark (Ishoy et al. 1999b). For example, the findings of the 1997 survey (Goss Gilroy Inc. 1998) mailed to the entire cohort of Canadian Gulf War veterans found an increase in self-reported respiratory disease (OR 1.35, 95% CI 1.16-1.57), bronchitis (OR 2.81, 95% CI 2.22-3.55), and asthma (OR 2.64, 95% CI 1.97-3.55) when adjusted for tobacco-smoking. The study by Eisen et al. (2005), described previously, is an exception in finding few differences among US veterans in respiratory symptoms and self-reported respiratory diagnoses between deployed and nondeployed troops 10 years after the Gulf War. And some of the many studies that have conducted factor analyses on reported symptoms have found respiratory factors (e.g., Cherry et al. 2001a; Cherry et al. 2001b; Hotopf et al. 2004). Of particular interest, some of the UK reports that found differences in respiratory symptoms and self-reported respiratory diagnoses have included comparisons of those deployed to the Gulf War with those deployed to Bosnia (Nisenbaum et al. 2004; Unwin et al. 1999). The Unwin et al. (1999) study found that the risk of self-reported asthma and bronchitis was higher in the Gulf