"We were mainly interested in events that can cause feelings of helplessness," says the study's author, Johanna M. Mooy, MD, PhD, of the Institute for Research in Extramural Medicine at Vrije Universiteit in the Netherlands. "We did not find an association between work-related events and type 2 diabetes," Mooy writes, but having "a high number of rather common major life events" was related to diabetes risk.
The study involved more than 2,000 men and women between 50 and 74 years old selected randomly from among the citizens of Hoorn, a Dutch city. None had ever been previously diagnosed with type 2 diabetes. A questionnaire helped to gauge the serious events that had occurred in each volunteer's life during the past five years. The subjects were then tested for diabetes and had their body fat measured.
Among the events listed on the checklist were child-and-partner-related problems (including illness or death), long-term financial problems, moving from a house, death of a friend, and end of an intense relationship. Work-related events included retirement, disability, and forced job change. "Our premise is that these kinds of experiences, such as the death of a loved one, cause major psychological stress, including feelings of helplessness, in almost every individual," Mooy says.
The researchers compared the numbers of stressful events that each volunteer checked, and factored in which volunteers were found to have diabetes. It turns out that, among single stressful events, the death of a partner or moving from a house carried a significantly higher risk for diabetes. And the more stressful personal events participants reported, the more likely they were to have diabetes. Three or more such events significantly increased the risk of diabetes, the study showed.
The link found between stress and diabetes had nothing to do with family history of diabetes, physical activity, heavy alcohol use, or low levels of education -- factors that have previously been shown to increase a person's risk of developing diabetes, Mooy says.
Do the effects of major life traumas last long enough to contribute to diabetes risk? While recovery periods vary between individuals, "very few recover from the death of a loved one within weeks, even if they have high coping ability or enjoy strong social support," Mooy says. "Thus, major life events may well contribute to the onset of diabetes, at least in individuals already at risk for diabetes."
The Dutch team's findings contribute to an unfolding theory that facing stressful situations with a helpless attitude can trigger a cascade of hormone-related changes that affect insulin production. Unlike other studies, though, this one did not find that excess body fat was a risk factor for diabetes.
Rich Wender, MD, chairman of family medicine at Thomas Jefferson University in Philadelphia, reviewed the study for WebMD. "What this study was aiming to show is that what happens in our thoughts and emotions is linked to our brain chemistry ... [which] has a profound impact on what happens to the body," he says. "I don't think they proved it beyond a shadow of a doubt; I think they added fuel to the fire."
Another theory, Wender says, is that stress makes people less interested in taking care of themselves. "There is an established link between emotions, your thoughts, and your health, and that goes well beyond diabetes," he says. "Those links occur because those stressful events change how we take care of ourselves, whether we are committed to exercise, whether we seek care, whether we get appropriate rest, whether we worry about food choices."
Traumatic events like these create a vulnerable time in one's life, Wender says. And the best way to cope is with a social network that provides support and heightens self-esteem.