“The prevalence of mild-to-moderate and severe cases was 39% and 6%, respectively, among 1,155 Gulf War veterans compared with 14% and 0.7% among 2,520 nondeployed personnel,” according to the study.
“This study and subsequent ones demonstrated that 10% to 15% of population suffers a syndrome like this,” Dr. Clauw said. “…Yet [veterans] with these symptoms were labeled as having Gulf War syndrome rather than fibromyalgia or irritable bowel syndrome.”
Veterans experiencing chronic multisymptom illness were more likely to experience tension or migraine headaches; affective disorders; temporomandibular joint syndrome; weight fluctuations; night sweats; weakness; sleep disturbances; cognitive difficulties; ear, nose, and throat complaints; vestibular complaints; and noncardiac chest pain, among other symptoms. “Any of you who see fibromyalgia patients sees these symptoms,” Dr. Clauw said.
Search for a Cause
Dr. Clauw and other investigators set out to find possible causes for this symptom cluster. One angle considered was how often similar symptoms occur after natural disasters (e.g., hurricanes and earthquakes) or manmade disasters (e.g., the Three Mile Island accident in Pennsylvania in 1979).3 While conducting research for a review article on this topic, Dr. Clauw said a few things became clear. “Until that time in 2003, natural disasters led to very few incidences of mood disorders or post-traumatic stress disorder and even smaller increases of chronic fatigue syndrome,” he noted. “In manmade disasters, there were fairly high rates of fibromyalgia and pain at different rates.”
However, Dr. Clauw said that Hurricane Katrina somewhat changed this trend, because a large number of physical and psychological symptoms have been associated with the disaster. “Katrina started as a natural disaster and then became a manmade disaster because of the way it was handled,” he said.
The research revealed that natural disasters may cause less pain and fewer other symptoms because of the rally of human support that follows them. “The hypothesis is that, with natural disasters such as hurricanes, floods, and fires, there are a lot of people who help and come together—people don’t feel out alone on an island, and there’s not the worry of exposures [to something toxic],” Dr. Clauw said.
A sense of support from others, along with a sense of control over what is happening in one’s environment, may make a difference in triggering illness such as that experienced by the Gulf War veterans, Dr. Clauw said. He gave the analogy of working hard at a job that one enjoys versus being asked to do a short but unenjoyable task someone else requests—the latter may cause more stress even though it takes less time. “There’s a lot of work right now on instilling resiliency and giving people a sense of control and support,” he said.
Genes and Gender
Central pain conditions seem to also be more common in women—although more men than women were sent to the first Gulf War, the women who did go experienced a higher rate of chronic multisymptom illness. Additionally, genetic underpinnings are a known trigger. At least four genes are associated with pain sensitivity, and these have been shown to be more common in fibromyalgia, irritable bowel syndrome, and other conditions, according to Dr. Clauw.
