Complex Factors in the Etiology of Gulf War Illness: Wartime Exposures and Risk Factors in Veteran Subgroups
– Source: Environmental Health Perspectives, Sep 19, 2011
By Lea Steele, et al.
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Background: At least one fourth of U.S. veterans who served in the 1990-1991 Gulf War are affected by the chronic symptomatic illness known as Gulf War illness (GWI). Clear determination of the causes of GWI has been hindered by many factors, including limitations in how epidemiologic studies have assessed the impact of the complex deployment environment on veterans’ health.
Objective: To address GWI etiologic questions by evaluating the association of symptomatic illness with characteristics of veterans’ deployment.
Methods. Veteran-reported wartime experiences were compared in a population-based sample of 304 Gulf War veterans: 144 cases who met pre-established criteria for GWI and 160 controls.
Analyses considered veteran subgroups and confounding among deployment variables.
Deployment experiences and the prevalence of GWI differed significantly by veterans’ location in theater.
Among personnel who were in Iraq or Kuwait, where all battles took place:
• GWI was most strongly associated with using pyridostigmine bromide* pills (OR=3.5, CI=1.7-7.4) [Note: an odds ratio of 1.0 would indicate no increased odds of GWI vs controls. An OR of 3.5 would indicate 250% increased odds of subsequent GWI, on average, among those using pyridostigmine bromide pills.]
• And being within one mile of an exploding SCUD missile (OR=3.1, CI=1.5-6.1).
For veterans who remained in support areas:
• GWI was significantly associated only with personal pesticide use,
• With increased prevalence (OR=12.7, CI=2.6-61.5) in the relatively small subgroup who wore pesticide-treated uniforms, nearly all of whom also used skin pesticides. [The OR of 12.7 indicates 1,170% greater odds of subsequent GWI in this subgroup vs. controls.]
Combat service was not significantly associated with GWI.
Findings support a role for a limited number of wartime exposures in the etiology of GWI, which differed in importance with the deployment milieu in which veterans served.
[* Ed Note: Pyridostigmine bromide is a drug that was used in hopes of preventing death from possible exposure to the ‘nerve gas’ Soman. It was a drug that had been tested only in animals for that purpose but received FDA approval as an investigational agent only for use by military personnel in combat. As a drug, it is used as a muscle stimulant for those with the autoimmune neuromuscular disorder myasthenia gravis. It is believed to ‘Facilitate myoneural junction impulse transmission by inhibiting acetylcholine destruction by cholinesterase.’ According to this article, of the 64 pesticides used during the Gulf War, 15 have been designated ‘pesticides of concern’ including permethrin, used on uniforms; DEET; and lindane powder, also applied to uniforms. Notably, for example, applications of permethrin where used averaged 30 per month vs. the recommended 1 every six weeks.]
Source: Environmental Health Perspectives, Sep 19, 2011. http://dx.doi.org/10.1289/ehp.1003399, by Steele L, Sastre A, Gerkovich MM, Cook MR. Institute of Biomedical Studies, Baylor University, Waco, Texas; Midwest Research Institute, Kansas City, Missouri; Department of Biomedical and Health Informatics, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri, USA. [Email: Lea_Steele@baylor.edu]