turn, this was thought potentially to cause “physiological and psychological changes” that might lead to chronic fatigue, mood-cognition, and musculoskeletal complaints.
In a population-based analysis, Ismail and associates (1999) identified three factors that accounted for 20% of the variance in UK Gulf War veterans: mood-cognition, respiratory symptoms, and peripheral nervous system symptoms. Comparison groups included cohorts of veterans who either served in Bosnia or were nondeployed. Many of the symptoms present in the Gulf War veterans were also present in Bosnian veterans.
Kang et al. (2002) performed another population-based factor analysis of 48 symptoms in larger cohorts of veterans either deployed (10,423 cases) or not deployed (8960) in the Gulf War. The study initially targeted 15,000 deployed veterans and 15,000 nondeployed veterans. One cluster of four symptoms was found to predominate (in mild or severe forms) in a subset of the Gulf War veterans (n = 277, 2.4%), who had also enhanced exposures to risk factors. A significantly higher prevalence of all 48 symptoms was observed among Gulf War deployed veterans compared to the nondeployed veterans (Kang et al., 2000). The four most frequently reported symptoms were runny nose, headache, unrefreshing sleep, and anxiety. Numerous chronic medical conditions—sinusitis, gastritis, and dermatitis—were reported more frequently by Gulf War veterans; many were reported about twice as often. The symptoms included blurred vision, loss of balance/dizziness, tremors/shaking, and speech difficulty. At least three of these four symptoms were present in 877 (7.7%) of the deployed veterans compared with 175 (1.8%) of the nondeployed veterans. The corresponding risk factors were consumption of contaminated food (for example, contaminated with oil or smoke), exposure to toxins (paint, solvents), and bathing in or drinking contaminated water. Kang and colleagues noted that a majority of cases (69%) with this set of four symptoms also met criteria for PTSD. Reciprocally, of cases meeting criteria for PTSD, about 11% experienced all four of these symptoms. Thus, these cases showed considerable overlap with PTSD. Also, when compared with the 6730 nondeployed veterans with none of the four symptoms, this group of 277 veterans had a higher incidence of other medical conditions, such as diarrhea, migraines, lumbago, hypertension, and tachycardia.
Ishoy et al. (1999a) conducted an epidemiological cross-sectional survey of 821 Danish veterans who had served as peacekeepers and in humanitarian relief in the Persian Gulf between April 1991 and January 1996, an interval that commenced after conclusion of the war. The veterans had a higher prevalence of neuropsychological, gastrointestinal, and skin symptoms when compared to controls. The neurological complaints included difficulty concentrating, sleep disturbance, fatigue, depression, headache, speech disturbances, and blurred vision. They also had more ICD-10 medical diagnoses compared with controls. Overall, the prevalence of these symptoms was about 20% greater, roughly comparable to the prevalence of such symptoms in US Gulf War veterans. Particularly striking was the development of these symptoms in a cohort whose tenure in the gulf began after conclusion of active war hostilities, implicating some common component of the experience that was, as the authors suggested, “independent of the actual war action.”
Responses from the Iowa Persian Gulf Study were used by Doebbeling to explore whether there was a Persian Gulf War illness. The 1896 deployed veterans and 1799 nondeployed veterans were surveyed in 1995-1996 about the presence of 137 symptoms; the prevalence of symptoms was significantly increased in deployed (50%) compared with the nondeployed veterans (14%). Factor analyis identified three symptom clusters (somatic distress, psychological distress, and panic) in both the deployed and nondeployed veterans.