Deborah Brauser
February 11, 2014
For the first time, eating disorders have been linked to adult-onset diabetes.
A large survey study of more than 52,000 adults in 19 countries showed that individuals with binge eating disorder or bulimia nervosa were more than twice as likely to have diabetes.
The study also showed that individuals with depression or intermittent explosive disorder were 30% and 60%, respectively, more likely than those without these disorders to have a diabetes diagnosis.
Lead investigator Peter de Jonge, PhD, told Medscape Medical New that the “particularly strong association” found between eating disorders and diabetes was surprising to him.
“I was aware of the literature regarding an association between depression and diabetes, but this [new study] really adds to the literature,” said Dr. de Jonge, who is a professor at the Interdisciplinary Center for Psychopathology and Emotion Regulation at the University Medical Center Groningen in the Netherlands.
“This is speculative, as the data are not detailed enough to fully confirm this, but these findings suggest that there might be a lifelong pathway in which persons first develop impulse control disorders and depression, which may gradually develop into diabetes. And the role of diet may be significant in this pathway,” he added.
The investigators note that this is the first study to show an association between impulse control disorders and diabetes.
The study was published online January 30 in Diabetologia.
International Study
“No studies have evaluated whether the frequently observed associations between depression and diabetes could reflect the presence of comorbid psychiatric conditions,” write the researchers.
So they sought to examine the association between a self-reported clinical diagnosis of diabetes and 16 disorders from the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV), including mood, anxiety, impulse control, and substance use disorders.
The investigators performed face-to-face in-house surveys of 52,095 individuals older than 17 years from the Netherlands, the United States, Colombia, Mexico, Peru, China, Japan, New Zealand, Belgium, France, Germany, Italy, Romania, Spain, Portugal, Israel, Iraq, Poland, and Northern Ireland.
The World Health Organization Composite International Diagnostic Interview was used to retrospectively determine the prevalence and age at onset of any psychiatric illness.
Results showed that 2508 of the survey participants were diagnosed with diabetes mellitus (mean age at onset, 50.3 years).
The highest lifetime prevalence rates for mental disorders were found for major depression at 11.3%, followed by specific phobia at 7% and alcohol abuse at 5.8%. In addition, 1.8% had intermittent explosive disorder, 0.9% had binge eating disorder, and 0.5% had bulimia nervosa.
Mechanism Unclear
Of the 16 disorders examined, all except obsessive-compulsive disorder showed a significant unadjusted association with a diabetes diagnosis.
However, after adjusting for “lifetime comorbidity until the age of diabetes onset,” only binge eating disorder (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.7 – 4.0), bulimia nervosa (OR, 2.1; 95% CI, 1.3 – 3.4), intermittent explosive disorder (OR, 1.6; 95% CI, 1.1 – 2.1), and major depressive episode/dysthymia (OR, 1.3; 95% CI, 1.1 – 1.5) remained significantly linked to diabetes.
The investigators note that the large sample size was 1 of the study’s biggest strengths. Limitations cited include the retrospective assessment of the mental disorders, the self-report of diabetes, not being able to distinguish between type 1 and type 2 diabetes, not including more mental disorders, such as schizophrenia, and that they did not stratify per country or culture.
“Stratifying by country would have led to insufficient numbers of subjects with which to conduct the multivariable models, while stratifying for culture would result in rather arbitrary decisions,” they write.
Another limitation was that the study was not designed to speculate about mechanism of action.
Instead, it documented strong associations “in a large population-based sample that was less biased than the existing registry studies,” write the researchers.
Overall, the findings “support the focus on depression as having a role in diabetes onset, but suggest that this focus may be extended towards impulse control disorders,” they add.
Three of the 26 study authors have reported several possible financial conflicts, which are fully listed in the original article. The other authors, including Dr. de Jonge, have reported no relevant financial relationships.
Diabetologia. Published online January 30, 2014. Abstract