ALS risk has waned among Gulf War veterans
 

ALS risk has waned among Gulf War veterans
Wed Jun 18, 2008 10:44pm IST


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[-] Text [+] By Michelle Rizzo

NEW YORK (Reuters Health) -The apparent increase in risk of developing amyotrophic lateral sclerosis, or ALS, among veterans of the 1991 Gulf War was limited to the decade following the war, a new study shows.

"Recent reports indicate that veterans of the first Gulf War experienced a 2-fold elevated risk of ALS during the decade after the war had ended," Dr. Ronnie D. Horner, of the University of Cincinnati Medical Center, Ohio, and colleagues write in the medical journal Neuroepidemiology.

ALS is commonly known as Lou Gehrig disease. Why Gulf War vets might be prone to the disease is not known, and indeed the finding of an excess risk is controversial.

To investigate further, the researchers looked at the numbers again. A total of 124 confirmed cases of ALS were identified among the 2.5 million military personnel who were on active duty between 1991 and 2001. Of these 124 cases, 48 occurred among the 696,118 military personnel who served in the Persian Gulf region during that time.

Overall, 33 of the 48 cases (69 percent) developed the disease prior to age 45 years; that compared to 49 of the 76 ALS cases (64 percent) in personnel who had not been deployed to the Persian Gulf region.

The researchers found that veterans deployed to the Persian Gulf region during the war had an increased risk of ALS until 1996, with the risk tapering off thereafter. Conversely, the ALS risk level remained fairly constant during the decade after the war among military personnel who were not deployed to the Gulf Region.

This pattern indicates that among the Gulf War personnel who developed ALS, "exposure to the cause or causes occurred at a common point in time or that the cause was at a common source," Horner said in an interview with Reuters Health. "This finding may help to narrow the array of possible causes of the outbreak."

"Our focus is now on identifying the cause of the outbreak," the researcher continued. To this end, he and his colleagues at Duke University and the Durham VA Medical Center, North Carolina, have completed "a spatial analysis of the movement through the war zone of the troop units from which the ALS cases subsequently arose."

The investigators are also preparing a study that will add a time dimension to these spatial findings. "The spatial analysis only tells us if there are geographic areas in the war zone where the risk of developing ALS was elevated," Horner explained. "We need to know if the risk in those areas is associated with a specific point in time."

"If we know where to look for the cause and when to look for it, we may be able to discover what happened," he concluded. "Once we know what happened, we can then begin to think about ways to prevent future occurrences ... Moreover, as we develop our understanding of why the disease occurs, this knowledge may also lead to therapies."

SOURCE: Neuroepidemiology, July 2008.

http://in.reuters.com:80/article/hea...86198920080618