Wayne State University School of Medicine researchers may have discovered why people exposed to war are at increased risk to develop chronic problems like heart disease years later. And the culprit that links the two is surprising.
Beginning in the mid-2000s, WSU researchers interviewed a random sample of 145 American immigrants who left Iraq before the 1991 Gulf War, and 205 who fled Iraq after the Gulf War began. All were residing in metropolitan Detroit at the time of the study. Study subjects were asked about socio-demographics, pre-migration trauma, how they rated their current health, physician-diagnosed and physician-treated obstructive sleep apnea, somatic disorders and psychosomatic disorders. Those who left Iraq after the war began and suffered from mental disorders such as post-traumatic stress disorder (PTSD) and depression, and self-rated their physical health as worse than their actual health, were 43 times more likely than pre-Gulf War immigrants to report obstructive sleep apnea (30.2 percent versus 0.7 percent) and later develop major chronic health issues such as cardiovascular disease.
"I was surprised, but we had a specific theory we wanted to test. Changes in the stress system would contribute to sleep apnea. What happens? Maybe it's the stress that leads to this fractured sleep," said Bengt Arnetz, M.D., Ph.D., M.P.H., School of Medicine professor of occupational and environmental health, deputy director of the Institute of Environmental Health Sciences at Wayne State, and the study's principal investigator and first author. "No one had explored this possible link before, although basic research suggests it as plausible."
The results are featured in the October 2012 issue of Psychosomatic Medicine, the peer-reviewed journal of the American Psychosomatic Society.
According to the article, "Obstructive Sleep Apnea, Post-traumatic Stress Disorder, and Health in Immigrants," obstructive sleep apnea occurs when the muscles supporting the soft palate at the back of the throat relax, but less is known about the reasons behind this neuromuscular malfunctioning.
"It's a known fact that the more exposure to violence you have, the more likely you are to report PTSD and depression, and the worse your self-rated health is, the more likely your actual health will suffer in five to 10 years," Arnetz said.
Hikmet Jamil, M.D., Ph.D., professor of occupational and environmental health in WSU's School of Medicine, and Thomas Templin, Ph.D., research professor in WSU's College of Nursing, also contributed to the article.
The obstructive sleep apnea and chronic disase link has been observed among many trauma-exposed populations, including refugees, Arnetz said.
"Iraqis were exposed to harsh conditions during the entirety of Saddam Hussein's more than 20 years of reign. However, trauma and environmental exposures increased measurably and dramatically after the initiation of the 1991 Gulf War," the article states.
The study can now be used as a model for other populations, including U.S. soldiers returning home from battle.
The multidisciplinary study brought together mental health research, sleep research and chronic disease research, Arnetz said.
He and Jamil were partially supported by the National Institute of Mental Health of the National Institutes of Health (award number R01MH085793).
To further test their ideas, the researchers plan to apply for funding from the National Institutes of Health to collaborate with Safwan Badr, M.D., professor and chief of the School of Medicine's Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, and Thomas Roth, Ph.D., director of the Henry Ford Sleep Disorders and Research Center.