June 12, 2009

Obesity, depression often occur together

A study confirms obesity and depression often occur together, even in children, U.S. researchers said in a statement.

Lead author Dr. Panagiota Pervanidou of Athens University Medical School in Athens, Greece, said cortisol is a steroid hormone that helps the body respond to stress but also has other functions -- including converting fat, protein and carbohydrates into energy. Normally, the hormone peaks in the early morning, starts to drop in late morning and reaches a low at night.

Our study indicates that cortisol abnormalities may underlie obesity and depression starting in childhood, Pervanidou said in a statement. However, depressed adults have slightly elevated cortisol levels at night the endocrine equivalent of chronic stress.

Chronic elevation of cortisol contributes to development of the metabolic syndrome, which includes abdominal obesity and other risk factors for diabetes and cardiovascular disease.

Pervanidou and colleagues measured cortisol five times a day in the saliva of 50 obese children and teenagers, as well as in their blood in the morning. All subjects completed the Children's Depression Inventory.

Cortisol levels in the saliva in the afternoon and evening correlated positively with symptoms of depression, the authors said. The more depressive symptoms that subjects reported, the higher the cortisol levels -- indicating obesity and depression may not only be related to behavior but also may have a hormonal link.

The study was presented at The Endocrine Society's 91st annual meeting in Washington.