TUESDAY, Sept. 12, 2006 (HealthDay News) -- A U.S. Institute of Medicine review of 850 studies finds no consistent pattern of illness among veterans of the first Gulf War, although some studies do suggest these veterans might be at heightened risk for amyotrophic lateral sclerosis (ALS) and brain tumors.
No one disputes that nearly one in every three of more than 700,000 veterans of the 1990-1991 conflict suffers from what experts call a "multi-symptom illness."
But so far, the IOM panel concluded, there is "no unique syndrome, unique illness or unique symptom complex in deployed Gulf War veterans."
The report, the fourth in a series that was commissioned by the Veterans' Affairs Administration, was released Tuesday. According to the Associated Press, the VA will use this data to decide whether Gulf War veterans are eligible for special benefits if they suffer from illnesses that can be linked to their service.
Dr. Lynn Goldman, a professor of occupational and environmental health sciences at Johns Hopkins University, chaired the panel that wrote the report. She said her team was hampered by a lack of studies that relied on objective measurements rather than veterans' self-reports of symptoms.
"It was expected that [self-reports] wouldn't be as reliable as studies with actual measurements," Goldman explained. "So, a lot of studies were trying to disentangle that. The disappointment was that really not too much emerged."
Some of what did emerge from the report:
- Higher rates of symptomatic illness among Gulf War veterans. "Twenty-nine percent of veterans meet a case definition of 'multi-symptom illness,' as compared with 16 percent of non-deployed veterans," the report found.
- Deployed veterans showed higher rates of certain medical conditions, such as fibromyalgia, chronic fatigue syndrome and "multiple chemical sensitivity," than non-deployed veterans.
- A higher risk of post-traumatic stress disorder, depression, anxiety and substance abuse among returning vets.
- No evidence of any increase in risk for neurological disorders among deployed vets, based on standard tests.
- No evidence of heightened risk for either cardiovascular disease, diabetes or cancer. However, one study suggested veterans exposed to nerve gas after the bombing of a poison gas dump at Khamisiyah, Iraq, could be at higher risk for brain cancer.
- Based on a handful of studies, it appears that deployed veterans may be at higher risk for ALS ("Lou Gehrig's disease"), a rare degenerative neurological disorder that normally strikes only five in every 100,000 Americans. Goldman stressed that, even at the risk level noted, the odds of any one veteran contracting ALS remains extremely low.
- No increased risk for respiratory illness among deployed vs. non-deployed veterans, based on objective pulmonary testing. However, soldiers with asthma did show an exacerbation of symptoms after wartime exposure to oil well fires.
- No heightened risk for birth defects in offspring of deployed veterans.
Goldman said the panel's findings were also hampered by a lack of baseline data -- measurements of the health of soldiers before deployment. She said the military also took few measurements of toxin levels on the ground during the first Gulf conflict, so making accurate determinations about soldiers' exposures to sarin, pesticides and other chemicals is nearly impossible.
"We felt strongly that in future conflicts there needs to be better exposure measures, and better information about people's baseline health status," Goldman said. She said that, to her knowledge, the U.S. military is gathering that type of information in the current Iraqi conflict.
One expert who's studied Gulf War Syndrome for years was less than impressed with the IOM report.
"This doesn't tell us anything we already didn't know," said Dr. Robert Haley, chief of the division of epidemiology at the University of Texas Southwestern Medical Center in Dallas.
Haley's ongoing work with animals is revealing potential links between sarin exposures in the first Gulf war and veterans' long-term heath complaints.
"This report is simply a review of all the epidemiology data, and the role of epidemiology is to raise hypotheses -- it never proves anything," Haley said.
The IOM's stated preference for "objective" data -- studies that do not rely on veterans' self-reported symptoms -- made it unlikely from the get-go that any solid conclusions would arise, Haley said. "They say there's no pattern or link, but it's not surprising that they reached that conclusion because they excluded all the studies that relied on veterans' reports of their own symptoms," he noted.
Goldman countered that the IOM did include studies of veterans' self-reports in its analysis. "But we were also quite clear about limitations," she said.
According to Goldman, the problem with self-reported symptoms is that people who go through traumatic experiences tend to pay more attention to their physical and mental states afterward than people who do not -- a phenomenon called "recall bias." Objective testing -- for example, lung-function or neurological tests -- often shows no increase in their symptoms compared to those seen in the normal population, however.
"So, do we prefer objective measurements and outcomes? Yes, we do," Goldman said.
She also pointed out that data from other countries echoes those of the IOM report. "There are a lot of studies conducted outside of the U.S. -- in Canada, the U.K., Australia and Denmark," Goldman said. "And the same differential in symptom reports was seen in all of those countries."
There's more on Gulf War illnesses at the U.S. Department of Veterans Affairs.