For the first time, scientists have found diseases like bulimia and binge eating disorder place people at risk for diabetes; previous research has shown that depression is also a risk factor for diabetes.
"I knew from the literature about the association between depression and diabetes but I was surprised that impulse control disorders, in particular, eating disorders stood out as having quite strong associations with diabetes," says Dr. Peter de Jonge, the study's lead author and a professor at the University of Groningen in the Netherlands.
People with bulimia and binge-eating disorder have trouble controlling their impulses, which could put them in danger of other serious medical problems later in life, experts say.
A team of scientists surveyed 52,000 people in their homes in 19 different countries including South Africa, China, Brazil and the U.S. and administered standardized psychiatric tests including the World Mental Health Surveys and the U.S. Health Interview Survey which asked participants, "Did a doctor or health professional ever tell you that you had any of the following illnesses...diabetes?"
The researchers' results showed people with diabetes were more likely to have depression and were also more likely to have bulimia, binge-eating disorder and a lesser known illness, called intermittent explosive disorder. This last illness is characterized by angry verbal outbursts and violent behavior, according to the Mayo Clinic.
Of those surveyed, 2,580 adults reported having adult-onset Type 2 Diabetes. Researchers only included participants whose diabetes began after age 21 and the average age the illness began was around age 50. Of the diabetic participants, 11 percent had major depression and about 4 percent had either bulimia, binge eating disorder or intermittent explosive disorder.
Though the figures may appear low, they would be even smaller in a sample of the general population, says de Jong. The odds of a bulimic or a person with binge eating disorder later having diabetes were still 4 times greater than someone without either eating disorder acquiring the disease, according to the study.
The majority of these mental disorders typically begin before the diabetes. This is significant because risk-factors precede the disease they areassociated with.
De Jong says the data cannot directly answer the question of why diabetes and depression or diabetes and eating disorders often coincide. He thinks it is possible that a dysfunction in the way people process glucose may make people more vulnerable for depression and impulse control, and ultimately lead to diabetes.
"I hope that this research may lead to suggestions for better treatments for depression and impulse control, and that in the long run it may help to prevent cases of diabetes by early intervention," he says.
The study was published in Diabetologia, the journal of the European Association for the Study of Diabetes.