Scientists are one step closer to determining the cause of and best course of treatment for a mysterious illness impacting one-third of all veterans who served in the 1991 Gulf War, according to a report published Wednesday.
Researchers at UC San Diego School of Medicine looked to study Gulf War Illness, a chronic multisymptom health condition that still impacts veterans more than 30 years after Operations Desert Shield and Desert Storm. Common symptoms include fatigue, headaches, muscle aches, joint pain, diarrhea, insomnia and cognitive impairment, according to the Department of Veterans Affairs.
The illness is commonly believed to have been triggered by veterans' exposure to environmental toxins. For three decades, the prevailing notion "is that inflammation is the driving force of the symptoms, as inflammatory markers are modestly higher in affected veterans than in healthy controls," according to the study, published Wednesday in Scientific Reports.
A rival hypothesis suggests mitochondria — the energy-producing organelle found in most cells — may be the true source of the symptoms.
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The UCSD team compared both theories side-by-side, assessing mitochondrial impairment and inflammation in 36 individuals, 19 of whom were veterans with GWI. The findings suggest that mitochondrial impairment, and not inflammation, is the main culprit for the illness's symptoms and should be the target for future treatments.
"This is a radical rethinking of the pathology of GWI," said corresponding author Dr. Beatrice Golomb, professor of medicine at UCSD School of Medicine. "For veterans who have long struggled to get effective care, this discovery could be a real game changer."
The researchers acquired muscle biopsies from the study participants and measured mitochondrial function. Inflammation was assessed through participants' blood levels of a specific protein which is a common marker of inflammation.
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They then compared this data to the participants' GWI symptoms and found that the severity of symptoms could be predicted by their degree of mitochondrial impairment, but not by their degree of inflammation, the report reads.
"Inflammation does appear to be linked to GWI, but our work suggests that it's actually a side effect of the primary issue, which is impaired cell energy," said Golomb.
The researchers also suggest that many GWI symptoms are the expected outcomes of mitochondrial dysfunction: For example, muscles rely heavily on fat to fuel them, so if mitochondrial dysfunction leads to impaired fatty acid oxidation in GWI patients, this could explain the muscle aches and physical fatigue they often experience, they write.
Additionally, the findings could have implications for other health conditions, including different forms of toxin exposure, aging and even heart disease -- many of which are marked by increased inflammation, yet often do not respond well to anti-inflammatory drugs.
"This is the first time that direct evidence for the mitochondrial hypothesis of GWI has been reported," said Golomb. "We hope that it will lead to improved treatment plans for the veterans who have long struggled with this mysterious illness."