NEW YORK (Reuters Health) - Military service members with symptoms of post-traumatic stress disorder (PTSD) are more likely to develop diabetes than their counterparts without PTSD symptoms, results of a new study hint.
While previous research has suggested that depression increases the risk of diabetes, the new study of more than 44,000 active duty service members suggests another stronger association.
"In our analyses, depression really was not significantly related to the increased risk of diabetes but PTSD was," lead author Dr. Edward J. Boyko of the Department of Veterans Affairs Puget Sound Health Care System in Seattle, Washington told Reuters Health.
PTSD is an anxiety disorder that can develop after exposure to a frightening event or ordeal in which grave physical harm occurred or was threatened. Events that may cause PTSD include violent personal assaults, naturally or human-caused disasters, accidents or military combat.
People with PTSD can have a number of symptoms including persistent frightening thoughts and memories of the trauma or they may feel emotionally numb, especially with friends and loved ones. Sleep problems, detachment and an exaggerated startle response are other common symptoms.
It's possible that the stress response associated with PTSD could contribute to widespread inflammation in the body and lower sensitivity to the blood-sugar-regulating hormone insulin, which could lead to diabetes, researchers say.
Boyko and colleagues examined the health status of 44,754 service members who did not have diabetes when they were initially enrolled in the Department of Defense's large ongoing Millennium Cohort Study. Three years later, 376 study participants -- or about 3 per 1000 -- reported they had been newly diagnosed with diabetes.
Those who developed type 2 diabetes (the kind closely linked to obesity) were much older than those who did not. They were also more apt to be overweight or obese, African American or Asian, male, to have PTSD symptoms and to be no longer with the military.
When the researchers factored out age, gender, body weight, race, and other variables that might increase the risk of diabetes (as well as military service characteristics and other mental health conditions), only PTSD symptoms remained significantly associated with an increased risk of diabetes. The risk of diabetes was more than twofold higher in the presence of PTSD symptoms.
In the journal Diabetes Care, Boyko and colleagues emphasize that their study has several limitations. For instance, the presence of diabetes or PTSD or any of the other conditions studied were self-reported by the participants and not medically confirmed. In addition, there may be a bias in favor of detecting diabetes in people being treated for PTSD, the researchers say.
The findings don't explain why there may be a link between PTSD and diabetes. It's possible, for instance, that drugs prescribed for PTSD, or some other factor not studied, could raise the risk of diabetes.
It's estimated that more than 23 million, or nearly 11 percent, of US adults aged 20 and older have type 2 diabetes. And a recent study found that more than one-third of US veterans seen at VA hospitals after serving in Iraq or Afghanistan were found to have PTSD or another mental health disorder.
Before doctors are encouraged to screen for diabetes in people who suffer from PTSD, the findings need to be confirmed, Boyko told Reuters Health.
"The American Diabetes Association has recommendations about when someone should be screened for diabetes, and right now we don't need to add PTSD to that," he said.
Diabetes Care, online May 18.