Among the general US population, the most frequent disorders in this group of diseases are diabetes, thyroid disease, and obesity. In Volume 4 of this series, diabetes was grouped together with cardiovascular diseases. Other specific endocrine, nutritional, or metabolic outcomes were not considered. In this chapter, we will present, separately, studies reporting hospitalizations for endocrine and metabolic disorders, mortality studies and studies reporting associations of deployment with specific diseases (diabetes, thyroid disorders, and obesity). See Table 4-3 for a summary of the primary papers reviewed for endocrine, nutritional, and metabolic disorders.
Diabetes is an endocrine disorder characterized by abnormally elevated levels of blood glucose. The two major types of diabetes are type 1 diabetes, caused by destruction of the pancreatic cells that produce insulin, and type 2 diabetes, caused by peripheral resistance to insulin action and impaired insulin secretion, with increased blood glucose levels. Type 1 usually affects young people, while type 2 is more prevalent in adults and is strongly associated with obesity.
Volume 4 included one primary study examining the association of deployment with 12 primary health outcomes, including diabetes, ascertained from a medical examination (Eisen et al., 2005). The study evaluated 1061 Gulf War deployed and 1128 nondeployed veterans who had been randomly selected from 11,441 Gulf War deployed and 9476 nondeployed veterans who previously participated in the National Health Survey of Gulf War Era Veterans and Their Families. Based on physical examinations conducted 10 years after the Gulf War, the prevalence of diabetes in deployed and nondeployed veterans was 4.2% and 3.5% (OR 1.52, 95% CI 0.81-2.85). Results for self-reported conditions were similar. A major limitation was the low participation rate, with only 53% of Gulf War veterans and 39% of nondeployed Gulf War veterans participating.
Studies relying on self-reported diabetes diagnoses, without additional confirmation, were considered secondary.
In a study of Kansas Gulf War veterans, prevalence of self-reported diabetes was similar in 1545 deployed veterans and 435 nondeployed (about 1% in both groups; OR 1.2, 95% CI 0.45-3.3) (Steele, 2000). Kang and colleagues (2000) found a very similar prevalence of self-reported diabetes in 11,441 deployed and 9476 nondeployed veterans (0.1% in both groups) in the National Health Survey of Gulf War Era Veterans and Their Families conducted in 1995. Among Seabee commands, no differences in prevalence of self-reported diabetes between Gulf War deployed Seabees (1.0%), those deployed elsewhere (0.9%), and nondeployed Seabees (1.6%) (OR 1.1, 95% CI 0.7-1.7 and OR 0.8, 95% CI 0.5-1.2, respectively) (Gray et al., 2002). Finally, in a multistate study of Gulf War deployed veterans (McCauley et al., 2002), being