Tuesday, December 2, 2008

Abdominal Fat Tied to Depression

The December issue of Archives of General Psychiatry, one of the JAMA/Archives journals, indicates that older adults with symptoms of depression appear more likely to gain abdominal fat. Oddly, these results don't appear to mean that there is a gain in overall fat for depressed adults, but there is definitely an issue with fat around the middle.

Background information provided in the Archives piece says that about 10 percent to 15 percent of older adults have symptoms of depression. “Depression has been associated with the onset of diabetes, cardiovascular disease and cardiac mortality [death],” the authors write. “To better prevent occurrence of these major disabling and life-threatening diseases, more insight into underlying mechanisms relating depression to these disorders is needed.”

Nicole Vogelzangs, M.Sc., of VU University Medical Center, Amsterdam, the Netherlands, and her colleagues studied 2,088 adults age 70 to 79 years. Participants were screened for depression at the beginning of the study and their overall and abdominal obesity was recorded then and again five years later. Measures of overall obesity included body mass index and body fat percentage, while abdominal obesity was assessed using waist circumference and a number of sophisticated measurements taken by lab instruments.

At the beginning of the study, 4 percent of participants had depression. After adjusting for sociodemographic and other characteristics associated with weight changes, depression was associated with an increase in abdominal fat over five years. “Such an association was not found for an increase in overall obesity and also appeared to be independent of changes in overall obesity, suggesting that depressive symptoms are rather specifically associated with fat gain [only in this] region,” the authors write.

There are several mechanisms by which depression might increase abdominal fat. Chronic stress and depression may activate certain brain areas and lead to increased levels of the hormone cortisol, which promotes the accumulation of abdominal fat. Individuals with depression may have unhealthier lifestyles, including a poor diet, that could interact with other physiological factors to produce an increase in obesity in this part of the body.

“This could also help explain why depression is often followed by diabetes or cardiovascular disease. Future research should further disentangle these mechanisms because this will yield important information for prevention or treatment of depression-related health consequences," state the authors.


No comments: