The Chicken-And-Egg Theory Of Depression, Diabetes

Are depression and diabetes linked?

According to a study released Tuesday in the Journal of the American Medical Association, there is interplay between type 2 diabetes and depression.

Working on the assumption that depressed people are less physically active and consume more calories, this study looked at the chicken-and-egg theory; does depression cause diabetes, or diabetes cause depression?  

Researchers at Johns Hopkins University School of Medicine in Baltimore tracked 5,201 people, ages 45 to 84, for about three years. They did not have type 2 diabetes.

After three years, those with symptoms of depression were 42 percent more likely to develop diabetes than those without symptoms of depression.  The more serious the depression, the higher the risk of developing diabetes. 

Even when you factor out other risks such as obesity, the depressed patients still had a 34 percent higher risk of diabetes.

Dr. Sherita Hill Golden of Johns Hopkins, told Reuters that depression increases inactivity and a tendency to eat more,  "and those are all known risk factors for type 2 diabetes. So it seems that some of the adverse health behaviors associated with depressive symptoms were an important component of that relationship (between depression and diabetes)."

The stress hormone, cortisol, may be to blame as well.  Elevated cortisol can inactivate the functioning of insulin and encourage fat around the belly, which is a risk factor for diabetes. Cortisol is involved in the “fight or flight” response to severe stress.

The researchers also looked at diabetics to determine whether they were more at risk for developing depression.  They found that diabetics had a 54 percent likelihood of developing depression.

Interestingly, those who did not know they had diabetes, or were on the border of developing diabetes, were about 20 percent less likely of developing depression than those without diabetes.

"That was a little bit of a surprise," Golden said to the Washington Post. The assumption is that having diabetes and monitoring for it might contribute to depression.

These findings echo a study out of Northwestern University last year that found people, age 65 and older, with symptoms of depression, were also more likely to develop diabetes.

These new revelations underscore the need to treat depression along with diabetes, and encourages additional awareness be taken into account by both doctors and patients.  

In a diabetic condition, the body does not produce or does not use insulin properly. Insulin takes sugar from foods and changes it into energy. Improperly functioning insulin means there are more sugars in the blood (blood glucose), which can destroy arteries and lead to heart attack, blindness, kidney failure, and nerve damage.

There will be an estimated 50 million people with diabetes by the year 2025, according to the American Diabetes Association.  The risk factors including being overweight, sedentary, and having a family history of diabetes.  

The Washington Post reports that researcher Golden serves on Merck & Co clinical diabetes advisory board. The funding for the study was provided by the U.S. National Institutes of Health.  #