Because the potential followup period after the Gulf War is still relatively short (less than 20 years) and the deployed veterans are still relatively young, it is not surprising that there has been no suggestion that Gulf War veterans are at increased risk for CHD as a result of deployment. Symptoms of chest pain are common, but they appear to be part of a nonspecific increase in general symptomatology (see “Symptom Reporting” later in this chapter) and do not themselves imply organic heart disease. Veterans of the Vietnam War are now at an age at which heart disease is prevalent, but again there is no consistent evidence that they are at increased risk as a result of their deployment. All five of the primary studies that assessed CHD in deployed and nondeployed veterans of the Gulf War and the Vietnam War showed no association; the two secondary studies were mixed.
Apart from nonspecific symptoms, the one long-term medical consequence of deployment in the Gulf War and other wars is a marked increase in the rate of PTSD. This appears to involve sensitization of the sympathetic nervous system, but the most consistent finding has been an increase in cardiovascular reactivity to simulated trauma manifested by exaggerated heart-rate and blood-pressure responses. This pattern was observed in three ambulatory studies: one found a significant increase (Muraoka et al. 1998), a second had an increase that did not quite achieve statistical significance (Beckham et al. 2004), and in the third only nighttime heart rate was increased (Haley et al. 2004). The studies that showed increased catecholamine production suggest that it may be explained by increased sympathetic nerve activity although the spectral analysis done by Haley et al. (2004) indicates that altered parasympathetic tone also contributes.
Although there may be an increase in resting heart rate, which is a risk factor for both hypertension and cardiovascular events, PTSD does not appear to lead to hypertension. The results for the association of PTSD and cardiovascular disease are mixed: one primary study and two secondary studies, all from the VES were positive, but one primary study on veterans of World War II and the Korean War found no association. The one primary study showed slight but not significant increase in total CHD in veterans with PTSD. Thus, there is suggestive, but not conclusive, evidence that PTSD increases the risk of CHD.
The committee concludes that there is inadequate/insufficient evidence of an association between deployment to a war zone and hypertension. The committee also concludes that there is inadequate/insufficient evidence of an association between deployment to a war zone and coronary heart disease.